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Estimates and Projections, Aboriginal and Torres Strait Islander Australians

Estimates and projections of the Aboriginal and Torres Strait Islander population for 2006 to 2031. Includes projections by sex and age groups.

Reference period
2006 - 2031

Assumptions

The Australian Bureau of Statistics (ABS) uses a cohort-component method for producing population projections for the period 2017 to 2031, based on the 2016 Census of Population and Housing. Using this method, assumptions made about future levels of fertility, mortality, and migration are applied to the 2016 Census base population (split by sex and single year of age) to obtain a projected population for the following year. The assumptions are then applied to this new (projected) population to obtain a projected population for the next year. This process is repeated until the end of the projection period is reached.

A similar method can also be used to produce population 'backcast' estimates which span the period 2006 to 2016. This technique requires assumptions to be made about past levels of mortality taking into account the most recent 2016 Census data to utilise the best quality estimates available. These are applied to the 2016 base population to obtain a 'reverse-survived' population for the previous year. The assumptions are then applied to this new reverse-survived population to obtain a population for the preceding year. This process is repeated until the first year of the estimation period is reached.

Estimates and projections presented in this release supersede estimates and projections based on earlier censuses. The assumptions used differ from those in previous publications. As a result, and in addition to the use of a different base population, which is significantly larger than the previous base population, the size, structure and components of the estimated and projected Aboriginal and Torres Strait Islander population are different to those previously published for the same period.

Span of estimates and projections

  • Backcast estimates of the Aboriginal and Torres Strait Islander population in this release span the period 30 June 2006 to 30 June 2016 and are available for Australia, the States and Territories and Remoteness Areas.
  • Projections of the Aboriginal and Torres Strait Islander population in this release span the period 30 June 2017 to 30 June 2031 and are available for Australia, States and Territories, Indigenous Regions and Remoteness Areas.
     

Given the large interval for which the assumptions are applied, backcast and projections data should be interpreted with caution.

Base population

  • The base population is the Aboriginal and Torres Strait Islander estimated resident population of Australia at 30 June 2016, derived from 2016 Census counts of Aboriginal and Torres Strait Islander Australians, adjusted for net undercount as measured by the Post Enumeration Survey (PES).
     

Estimates

Summary of assumptions

A single time series of Aboriginal and Torres Strait Islander estimates for the period 2006 to 2016 has been produced. 

Over this period life expectancy at birth is assumed to:

  • increase by 0.40 years per year for males and 0.25 years per year for females between 2011 to 2016
  • increase by 0.30 years per year for males and 0.20 years per year for females between 2006 to 2011.
     

Net interstate migration for each of the above two intercensal periods was based on levels observed in each respective intercensal period. 

Zero net overseas migration occurred across the entire series with no arrivals and departures.

Projections

Summary of projections

Assumptions have been formulated on the basis of past demographic trends, in conjunction with consultation with various experts and government department representative at the national and state/territory level. They do not attempt to allow for non-demographic factors (such as major government policy decisions, economic factors, natural disasters, epidemic or significant health treatment improvements) which may alter future demographic behaviour or outcomes.

Table 1 - Summary of assumptions
 Total fertility rateTotal paternity rateMale life expectancy at birthFemale life expectancy at birth
 babies per womanbabies per manyearsyears
High assumptionConstant fertility ratesAnnual increase of 2.0%Annual increase of 0.45 yearsAnnual increase of 0.35 years
Medium assumptionAnnual decrease of 1.0%Annual increase of 1.0%Annual increase of 0.40 yearsAnnual increase of 0.25 years
Low assumptionAnnual decrease of 1.5%Constant paternity ratesAnnual increase of 0.25 yearsAnnual increase of 0.20 years


Additional assumptions regarding the remaining demographic factors for the projections are:

  • constant interstate migration at levels observed in the 2016 Census
  • zero net overseas migration with no arrivals and no departures
  • zero unexplained growth in Aboriginal and Torres Strait Islander population.
     

Projections series

By considering the above assumptions, nine projection series were produced. Three main series have been selected from these to provide a range of projections for analysis and discussion in this publication. These series are referred to as series A (high), series B (medium) and series C (low). Detailed information on these and the remaining projection series are available in the data cubes. 

Table 2 - Projection series, assumptions used(a)
Life expectancy at birth
  Low increaseMedium increaseHigh increase
CONSTANT PATERNITY RATES
Fertility rates
 Constant . .. .
 Annual decrease of 1.0%. .F. .
 Annual decrease of 1.5%C. .. .
1% ANNUAL INCREASE IN PATERNITY RATES
Fertility rates
 Constant. .D. .
 Annual decrease of 1.0%IBH
 Annual decrease of 1.5%. .E. .
2% ANNUAL INCREASE IN PATERNITY RATES
Fertility rates
 Constant. .. .A
 Annual decrease of 1.0%. .G. .
 Annual decrease of 1.5%. .. .. .

. . not applicable
a. Levels of interstate migration as observed in the 2016 Census and zero overseas migration apply to all series.

Which series to use

The three main series respectively imply a high, medium and low overall growth rate of the Aboriginal and Torres Strait Islander population. It is expected that series B will be the most appropriate choice for most users. The ABS will be using series B in calculating fertility and mortality rates for inclusion in the annual Births and Deaths publications. 

The effect of alternative assumptions on the size of the future Aboriginal and Torres Strait Islander population is described in the Chapter: Sensitivity to Projection Assumptions.

The population projections are not intended as forecasts or predictions, but are illustrations of growth and change in the population that would occur if assumptions made about future demographic trends were to prevail over the projection period. Future uncertainty, along with the subjective nature of assessing current trends, means that using a range of possible outcomes rather then a single projection series acknowledges a range of the possible future size, distribution and age structure of Australia's Aboriginal and Torres Strait Islander population. 

There is also some level of uncertainty surrounding 2016 Aboriginal and Torres Strait Islander Census counts and population estimates on which the projections are based, as well as data quality issues relating to registered births and deaths of Aboriginal and Torres Strait Islander people. Information on data quality issues related to Aboriginal and Torres Strait Islander estimates and projections are available in the Quality Declaration. 

Fertility and paternity

The ABS Births collection identifies a birth as being an Aboriginal and/or Torres Strait Islander person where at least one parent identifies themselves as being of Aboriginal and Torres Strait Islander origin on the birth registration. These can be attributed to either:

  • Aboriginal and Torres Strait Islander mothers, including births where both the mother and father are Aboriginal and Torres Strait Islander
  • Aboriginal and Torres Strait Islander fathers and non-Indigenous mothers.
     

For simplicity, birth rates of Aboriginal and Torres Strait Islander mothers are referred to in this release as fertility rates, while birth rates where the father is Aboriginal and Torres Strait Islander and the mother's Indigenous status is non-Indigenous or not stated are referred to as paternity rates.

To produce population projections using the cohort-component method, assumptions for each year of the projection period are required for age-specific fertility rates, age-specific paternity rates and the Aboriginal and Torres Strait Islander sex ratio at birth.

Indigenous status of parents

Of the Aboriginal and Torres Strait Islander births registered in 2017:

  • 27% were births for which both parents identified themselves as being of Aboriginal and Torres Strait Islander origin on the birth certificate statement
  • 43% were births where only the mother was of Aboriginal and Torres Strait Islander origin (including births where paternity was not acknowledged or the father's Indigenous status was not stated)
  • 30% were births where only the father was of Aboriginal and Torres Strait Islander origin (including births where the mother's Indigenous status was not stated).
     
  1. Includes fathers whose Indigenous status was not stated.
  2. Includes mothers whose Indigenous status was not stated.

Source(s): Births Australia, 2017
 

The proportion of Aboriginal and Torres Strait Islander births attributed to Aboriginal and Torres Strait Islander mothers and/or Aboriginal and Torres Strait Islander fathers differs considerably between the states and territories. 

In 2017:

  • The Northern Territory had the highest proportion of births (43%) where both the mother and father were Aboriginal and Torres Strait Islander
  • Tasmania had the lowest proportion of births (12%) where both mother and father were Aboriginal and Torres Strait Islander
  • 39% of births in the Australian Capital Territory were to non-Indigenous mothers and Aboriginal and Torres Strait Islander fathers (11% in the Northern Territory).
     
  1. Includes fathers whose Indigenous status was not stated.
  2. Includes mothers whose Indigenous status was not stated.
  3. Includes Other Territories. 

Source(s): Births Australia, 2017
 

Sex ratio at birth

Population projections require an assumed sex ratio at birth in order to split total projected births into male and female births. The sex ratio for Aboriginal and Torres Strait Islander births registered in Australia fluctuates around 103 to 109 male births per 100 female births. A constant ratio of 105.6 males per 100 female births has been assumed for the duration of the projection period.

Fertility assumption

Three main assumptions have been made for future fertility rates of Aboriginal and Torres Strait Islander women:

  • Constant fertility rates at the 2017 level
  • An annual decline of 1.0% in fertility rates
  • An annual decline of 1.5% in fertility rates.
     

These assumptions were primarily chosen on the basis of the declining trend in fertility as indicated by data from the 'children ever born' question asked in the Census. 

The same rate of decline in fertility rates have been assumed for each state and territory, Indigenous Regions and Remoteness Area.

Trends in fertility rates

Children ever born

Cohort fertility rates, based on the 'children ever born' question asked in the Census illustrate a decline in Aboriginal and Torres Strait Islander fertility over time. 

The number of children ever born provides information on actual fertility outcomes of women of different ages. In particular, the number of children ever born to women aged 40-44 year can be regarded as a measure of completed fertility; that is, on average how many children this group of women each had throughout their entire reproductive lifetimes. 

Aboriginal and Torres Strait Islander women aged 40-44 years had on average:

  • 3.97 babies per woman in the 1986 Census
  • 3.10 babies per woman in he 1996 Census
  • 2.84 babies per woman in the 2006 Census
  • 2.82 babies per woman in the 2011 Census
  • 2.77 babies per woman in the 2016 Census
     

The average number of children ever born to Aboriginal and Torres Strait Islander women has been declining for each age group over the past three decades. These declines, particularly in the younger age groups, indicate probable declines in the future overall level of Aboriginal and Torres Strait Islander fertility.

  1. Average number of children ever born calculated on assumption that women with 6 or more children had an average of 6.9 children.
  2. The children ever born question was not asked in the 1991 and 2001 Censuses.

Source(s): 1986,1996, 2006, 2001 and 2016 Censuses of Population and Housing
 

Total fertility rate

The total fertility rate (TFR), based on birth registrations, represents the average number of children a woman could expect to bear during her lifetime if she experienced current age-specific fertility rates at each age of her reproductive life. 

The TFR for Aboriginal and Torres Strait Islander women:

  • Was 1.9 babies per woman in 2001
  • Gradually increased to 2.5 in 2010, before slowly decreasing over the period 2012 to 2016
  • By 2017, increased to 2.3 babies per woman.
     

a. Births per Aboriginal and Torres Strait Islander woman.
b. Includes Other Territories.

Source(s): Births Australia, 2017
 

Choice of fertility assumption

In summary, while fertility rates based on birth registrations of Aboriginal and Torres Strait Islander children may provide some evidence for assuming constant or increasing Aboriginal and Torres Strait Islander fertility, cohort fertility rates based on the 'children ever born' question asked in the Census indicate long-term declines. Assumptions that take both sets of evidence into account have been made but with more emphasis given to the 'children ever born' data.

  • Low series: The magnitude and duration of any future changes in fertility rates are not possible to gauge accurately, but it's possible that a decline observed between 2012 to 2016 may continue during the projection period. On this basis, low series assumes an annual decline of 1.5%.
  • Medium series: assumes an annual decline of 1% which is equivalent to the decline in average children per Aboriginal and Torres Strait Islander woman in the last ten years.
  • High series: assumes constant fertility rate as observed in 2017.
     

Method used to produce fertility assumptions

Assumed age-specific fertility rates for Aboriginal and Torres Strait Islander women are based on three years of birth registrations (2015 to 2017) in order to minimise the effect of year-to-year fluctuations in registrations. These rates were adjusted to produce plausible numbers of projected births in the first year of the projection period in accordance with Aboriginal and Torres Strait Islander population estimates at younger ages.

Adjustment factors were calculated for each state and territory by taking the ratio of the number of Aboriginal and Torres Strait Islander children aged 0, 1 and 2 at 30 June 2016 to the number of births registered between 2015 and 2017. Differences in the two sources can be attributed to several factors, including:

  • net undercount
  • Census records for which Indigenous status was not stated
  • lags in the registration of births
  • differences in the method of identification between the Census and the Birth registration collection (for example, identified as Aboriginal and Torres Strait Islander in the birth registration but not on the Census form).
     

As rates are required on a financial year basis they were adjusted to account for the six-month period between the mid-point of the period 2015–17 (calendar year fertility rates) and 2016–17 (financial year fertility rates).

Assumed declines in fertility rates are applied uniformly across relevant age groups.

Table 3 - Assumed fertility rates, states and territories
AGE-SPECIFIC FERTILITY RATES(a)
 15–19(b)20–2425–2930–3435–3940–4445–49(c)TFR(d)
YEAR ENDED 30 JUNE 2017
NSW44.9114.4121.088.745.59.10.32.12
Vic.35.7101.3105.789.143.413.40.61.95
Qld51.3127.4122.291.046.111.00.82.25
SA49.5110.8115.684.146.97.40.52.07
WA68.8131.0118.878.641.710.40.42.25
Tas.30.3101.797.175.334.95.51.72
NT63.8123.0103.074.538.68.00.42.06
ACT23.877.278.592.246.414.11.81.67
Aust.(e)50.5119.5116.785.644.09.90.52.13
YEAR ENDED 30 JUNE 2031
NSW39.099.4105.177.039.57.90.31.84
Vic.31.088.091.877.437.711.60.51.69
Qld44.6110.7106.279.040.09.60.71.95
SA43.096.2100.473.140.86.40.51.80
WA59.8113.8103.268.336.29.00.31.95
Tas.26.488.484.465.430.34.81.50
NT55.5106.889.464.733.56.90.41.79
ACT20.767.168.280.140.312.21.61.45
Aust.(e)43.8103.8101.474.438.28.60.41.85

- nil or rounded to zero (including null cells)
a. Births per 1,000 Aboriginal and Torres Strait Islander women.
b. Includes births to mothers aged less than 15 years.
c. Includes births to mothers aged 50 years and over.
d. Births per Aboriginal and Torres Strait Islander woman.
e. Includes Other Territories.

Regional variations in fertility

Indigenous Regions

The projections in this release apply fertility assumptions for sub-state geographies by aggregating Indigenous Regions (IREGs) into two groups for each state and territory (except Tasmania and the Australian Capital Territory):

  • capital city IREG (for example, Adelaide IREG)
  • rest of state/territory IREGs combined (for example, Port Augusta IREG and Port Lincoln - Ceduna IREG combined).
  • Fertility rates for each of these groups were adjusted in a similar manner to state and territory rates to produce plausible numbers of projected births in the first year of the projection period in accordance with Aboriginal and Torres Strait Islander population estimates at younger ages.
     
Table 4 - Assumed total fertility rates(a), Indigenous regions
Indigenous Region30 June 201730 June 2031
Sydney IREG1.851.60
Rest of NSW2.261.96
Melbourne IREG1.581.37
Rest of Vic.2.382.07
Brisbane IREG1.891.64
Rest of Qld2.482.15
Adelaide IREG2.021.76
Rest of SA2.231.94
Perth IREG2.131.85
Rest of WA2.352.04
Tasmania IREG1.721.50
Darwin IREG2.031.77
Rest of NT2.081.81
ACT IREG1.671.46
Australia(b)2.131.85

a. Births per Aboriginal and Torres Strait Islander woman.
b. Includes Other Territories.

Remoteness Areas

Assumed fertility rates for Remoteness Areas were calculated and adjusted using the same technique as for the states and territories.

Table 5 - Assumed total fertility rates(a), Remoteness Areas
Remoteness Area30 June 201730 June 2031
Major Cities1.871.62
Inner and Outer Regional2.312.00
Remote and Very Remote2.302.00
Australia(b)2.131.85

a. Births per Aboriginal and Torres Strait Islander woman.
b. Includes Other Territories.

Paternity assumptions

The total paternity rate (TPR) is defined as the average number of Aboriginal and Torres Strait Islander babies born per Aboriginal and Torres Strait Islander father where the mother's Indigenous status is non-Indigenous or not stated, and is calculated in the same way as the TFR.

Three main assumptions have been made for future paternity rates:

  • constant paternity rates
  • an annual increase of 1.0% in paternity rates
  • an annual increase of 2.0% in paternity rates.
     

The same rate of increase in paternity rates has been assumed for each state and territory, Indigenous Region, and Remoteness Area.

Trends in paternity rates

As with the TFR, the time series of the TPR is based on population estimates which are not strictly comparable over time. Based on birth registrations, the TPR has been slowly increasing over more than a decade, from 0.77 births per Aboriginal and Torres Strait Islander male in 2001 to 1.06 in 2017.

  1. Births to Aboriginal and Torres Strait Islander males, where the mother's Indigenous status was non-Indigenous or not stated. The TPR is calculated in the same way as the TFR.
  2. Estimated resident population based on the 2016 Census.
     

Choice of paternity assumption

The 'children ever born' question is not asked of males in the Census. Therefore, there is no reliable source other than birth registrations for calculating paternity rate.

  • Low series: assumes constant paternity rate over the projection period.
  • Medium series: paternity rate calculated from birth registration data has been slowly increasing over time and showed an increase of 1.1% during 2006 to 2016. To reflect this trend, medium series assumes an annual increase of 1% in paternity rate.
  • High series: the increase in paternity rate in the recent years might have been underestimated due to registration lags. Therefore, an annual increase in paternity rate of 2% is assumed for high series.
     

Method used to produce paternity assumptions

Assumed age-specific paternity rates for Aboriginal and Torres Strait Islander men are based on three years of birth registrations (2015 to 2017) where the mother's Indigenous status is non-Indigenous or not stated, which were then adjusted to ensure consistency with the Aboriginal and Torres Strait Islander population at younger ages. Assumed increases in paternity rates are applied uniformly across relevant age groups.

Regional variations in paternity

Indigenous Regions

Assumed paternity rates for IREGs were calculated and adjusted using the same technique as for the states and territories.

Table 6 - Assumed paternity rates, states and territories
AGE-SPECIFIC PATERNITY RATES(a)
 15-19(b)20-2425-2930-3435-3940-4445-49(c)TPR(d)
YEAR ENDED 30 JUNE 2017
NSW9.040.561.862.541.616.18.61.20
Vic.8.944.659.976.850.422.116.01.39
Qld7.335.547.750.634.213.66.80.98
SA7.733.448.642.130.014.85.40.91
WA5.920.328.832.621.89.04.70.62
Tas.9.244.677.369.548.123.97.71.40
NT0.46.011.310.97.93.33.20.21
ACT8.133.150.390.954.215.58.11.30
Aust.(e)7.232.946.648.632.813.57.30.94
YEAR ENDED 30 JUNE 2031
NSW10.346.671.071.847.818.59.91.38
Vic.10.351.368.988.258.025.418.41.60
Qld8.440.854.858.239.315.67.81.12
SA8.838.455.848.434.517.06.21.05
WA6.823.433.137.425.110.35.30.71
Tas.10.551.388.979.955.327.48.91.61
NT0.56.912.912.59.13.73.60.25
ACT9.338.057.8104.562.317.89.31.50
Aust.(e)8.337.853.555.937.715.58.41.09

a. Births to Aboriginal and Torres Strait Islander men, where the mother's Indigenous status was non-Indigenous or not stated, per 1,000 Aboriginal and Torres Strait Islander men.
b. Includes births to fathers aged less than 15 years.
c. Includes births to fathers aged 50 years and over.
d. Births to Aboriginal and Torres Strait Islander men, where the mother's Indigenous status was non-Indigenous or not stated, per Aboriginal and Torres Strait Islander man.
e. Includes Other Territories.

Table 7 - Assumed total paternity rates(a), Indigenous Regions
Indigenous Region30 June 201730 June 2031
Sydney IREG1.151.33
Rest of NSW1.221.40
Melbourne IREG1.191.37
Rest of Vic.1.641.88
Brisbane IREG1.311.50
Rest of Qld0.780.90
Adelaide IREG1.101.27
Rest of SA0.490.57
Perth IREG0.820.95
Rest of WA0.470.54
Tasmania IREG1.401.61
Darwin IREG0.530.61
Rest of NT0.080.10
ACT IREG1.301.50
Australia(b)0.941.09

a. Births to Aboriginal and Torres Strait Islander men, where the mother's Indigenous status was non-Indigenous or not stated, per Aboriginal and Torres Strait Islander man.
b. Includes Other Territories.

Remoteness Areas

Assumed paternity rates for Remoteness Areas were calculated and adjusted using the same technique as for the states and territories.

Table 8 - Assumed total paternity rates(a), Remoteness Areas
Remoteness Area30 June 201730 June 2031
Major Cities1.221.40
Inner and Outer Regional1.091.25
Remote and Very Remote0.240.28
Australia(b)0.941.09

a. Births to Aboriginal and Torres Strait Islander men, where the mother's Indigenous status was non-Indigenous or not stated, per Aboriginal and Torres Strait Islander man.
b. Includes Other Territories.

Mortality assumptions

To produce population projections using the cohort-component method, life tables are required for each year of the projection period. These are calculated in two steps:

  • life expectancy at birth for each projection year is assumed
  • life tables, based on the 2015 to 2017 age/sex structure of mortality, are generated to match the assumed life expectancies at birth.
     

Survivorship ratios from the life tables are then applied to the population by single year of age and sex.

Assumptions for mortality at lower geographical levels are based on 2015 to 2017 differentials between Australia and each state or territory, groups of Indigenous Regions, and Remoteness Areas.

Current life expectancy at birth

At the national level, Aboriginal and Torres Strait Islander life expectancy at birth for the period 2015 to 2017 is estimated to be 71.6 years for males and 75.6 years for females (see Life Tables for Aboriginal and Torres Strait Islander Australians, 2015–2017).

As survivorship ratios are required on a financial year basis, life expectancy at birth estimates are adjusted to account for the six-month period between the midpoint of 2015–17 (calendar year life expectancy) and 2015–16 (financial year life expectancy), resulting in life expectancy at birth of:

  • 71.4 years for Aboriginal and Torres Strait Islander males
  • 75.5 years for Aboriginal and Torres Strait Islander females.
     

Trends in life expectancy at birth

The ABS has compiled life tables for Aboriginal and Torres Strait Islander Australians after each Census since 1996. Due to changes in the methods, the 2006, 2011 and 2016 estimates of life expectancy at birth are not comparable to estimates for earlier periods. Assumptions about future levels of Aboriginal and Torres Strait Islander life expectancy at birth can therefore only be based on observed trends over the two most recent intercensal periods. 

A study (Wilson, Condon and Barnes, 2007) found evidence that in the Northern Territory:

  • life expectancy at birth increased from 52 years for males and 54 years for females in the 1960's, to 60 years and 68 years respectively in recent years
  • improvements in infant mortality contributed to increases in life expectancy at birth between the late 1960's and early 1980's
  • Since then, life expectancy gains have been largely the result of improving mortality of people aged 45 years and over.
     

In addition alternative measures indicate some improvement in mortality of Aboriginal and Torres Strait Islander Australians between 1991 and 2005:

  • declines in mortality as measured by age-standardised death rates have been recorded in Western Australia and for females in the Northern Territory
  • declines in infant mortality have been recorded in Western Australia, South Australia and the Northern Territory.
     

For more information see The Health and Welfare of Australia's Aboriginal and Torres Strait Islander Peoples, Oct 2010, cat. no. 4704.0, Wang Z and Li SQ, 2010, Mortality in the Northern Territory 1967-2006, Health Gains Planning Information Sheet, Dec 2010, Northern Territory Government, Casuarina NT and SCRGSP (Steering Committee for the Review of Government Service Provision) 2011, Overcoming Indigenous Disadvantage: Key Indicators 2011, Productivity Commission, Canberra. 

Assumed life expectancy at birth

Three life expectancy at birth assumptions have been used to produce the three main series.

Table 9 - Life expectancy at birth, assumptions
AssumptionLife expectancy at birth - 30 June 2031
 MalesFemalesMalesFemales
Series A (a)Annual increase of 0.45 yearsAnnual increase of 0.35 years78.280.7
Series B (b)Annual increase of 0.40 yearsAnnual increase of 0.25 years77.479.2
Series C (c)Annual increase of 0.25 yearsAnnual increase of 0.20 years75.278.5

a. This assumes Aboriginal and Torres Strait Islander population life expectancies will increase at a lower rate than observed in 2011 to 2016 but at a higher rate than observed in 2006 to 2016.
b. This assumes Aboriginal and Torres Strait Islander population life expectancies will increase at the rate observed in 2006 to 2016.
c. This assumes Aboriginal and Torres Strait Islander population life expectancies will increase at the rate observed in the total Australian population life expectancies in the last 30 years.

State/territory variations in mortality

Aboriginal and Torres Strait Islander life expectancy at the national level has been calculated using an age-specific adjustment to allow for different patterns in mortality amongst different age groups. This adjustment could not be applied at the state and territory level. For this reason the Australian-level estimates are not strictly comparable with the state/territory level estimates. However, for the purpose of compiling estimates and projections, mortality differentials are calculated based on the relationship of 2015 to 2017 life expectancies at birth for each state/territory (without age adjustment) compared with Australia (with age adjustment).

Aboriginal and Torres Strait Islander life expectancy at birth differs between the states and territories. For the purposes of these projections, mortality differentials between each state/territory and Australia are calculated and applied to the assumed Australian life expectancies at birth to obtain assumed life expectancy at birth for the states and territories. This method assumes that the mortality differentials, based on those observed during 2015 to 2017, will remain constant throughout the projection period. 

Due to small numbers of deaths registered as Aboriginal and Torres Strait Islander it was not possible to produce Aboriginal and Torres Strait Islander life tables for Victoria, South Australia, Tasmania and the Australian Capital Territory. For the purposes of the projections it is assumed that life expectancy at birth for:

  • Victoria and Tasmania are the same as that for New South Wales
  • South Australia is the same as that for Western Australia
  • The Australian Capital Territory is the same as that derived for the Sydney Indigenous Region.
     
Table 10 - Aboriginal and Torres Strait Islander life expectancy at birth and mortality differentials(a), state and territories, 2015 to 2017
 Life expectancy at birthMortality differentials
 MalesFemalesMalesFemales
 yearsyears%%
NSW70.975.999100
Qld72.076.4101101
WA66.971.89395
NT66.669.99392
Aust.(b)71.675.6100100

a. Mortality differentials are calculated based on the relationship of 2015 to 2017 life expectancies at birth for each state/territory (without age adjustment), compared with Australia (with age adjustment).
b. Includes Other Territories.

Regional variations in mortality

Indigenous Regions

To apply assumptions on life expectancy at birth for alternative geographies, Indigenous Regions (IREGs) were aggregated into two groups for each state and territory (except Tasmania and the Australian Capital Territory):

  • capital city IREG (for example, Adelaide IREG)
  • rest of state/territory IREGs combined (for example, Port Augusta IREG and Port Lincoln - Ceduna IREG combined).
     

To account for under-identification of deaths of Aboriginal and Torres Strait Islander people at smaller geographic level, the number of registered deaths of Aboriginal and Torres Islander people for each IREG group in 2015 to 2017 was adjusted using state and territory adjustment factors from the 2016 to 2017 Census and deaths linked data. For more information about the derivation and use of adjustment factors in the compilation of Aboriginal and Torres Strait Islander life tables for the states and territories, see Life Tables for Aboriginal and Torres Strait Islander Australians, 2015–2017

A life table methodology was used to obtain life expectancy at birth for 2015 to 2017 for each IREG group using adjusted deaths in conjunction with 2016 Aboriginal and Torres Strait Islander populations for each IREG group. Differentials were calculated as the ratio of Aboriginal and Torres Strait Islander life expectancy at birth for each IREG group and Australia with age adjustment. This method assumes that under-identification of Aboriginal and Torres Strait Islander deaths is consistent across all regions within each state and territory as information on under-identification is not available at IREG level. Mortality differentials are assumed to remain constant throughout the projection period. 

Table 11 - Aboriginal and Torres Strait Islander life expectancy at birth and mortality differentials(a), Indigenous Regions, 2015 to 2017
 Male mortality differentialsFemale mortality differentials
 Capital city IREGRest of state IREG groupCapital city IREGRest of state IREG group
 %%%%
NSW10397102100
Qld1059810499
WA97929893
NT98929791
Aust.(b)100100100100

a. Mortality differentials based on the relationship of 2015 to 2017 life expectancies at birth for each capital city IREG and rest of state IREG group, compared with Australian life expectancy (with age adjustment).
b. Includes Other Territories.


As noted above, Aboriginal and Torres Strait Islander life tables were not produced for Victoria, South Australia, Tasmania and the Australian Capital Territory. The following differentials have been used for IREG groups in these states and territories:

  • Victoria: Melbourne IREG uses the Sydney IREG differential, the rest of Victoria IREG uses the rest of New South Wales IREG group differential
  • South Australia: Adelaide IREG uses the Perth IREG differential, and the rest of South Australia IREG group uses the rest of Western Australia IREG group differential
  • Tasmania uses the New South Wales state differential
  • The Australia Capital Territory uses the Sydney IREG differential.
     

Remoteness Areas

Aboriginal and Torres Strait Islander life expectancy at birth differentials for Remoteness Areas were calculated using the same method as that used for IREG groups. 

Table 12 - Aboriginal and Torres Strait Islander life expectancy at birth and mortality differentials(a), Remoteness Areas, 2015 to 2017
 Life expectancy at birthMortality differentials
 MalesFemalesMalesFemales
Remoteness Areayearsyearsyears (%)years (%)
Major Cities72.176.5101101
Inner and outer Regional70.074.89899
Remote and Very Remote65.969.69292
Australia(b)71.675.6100100

a. Mortality differentials based on the relationship of 2015 to 2017 life expectancies at birth for each Remoteness Area, compared with Australian life expectancy (with age adjustment).
b. Includes Other Territories.

Interstate migration assumption

One assumption has been made for future net internal migration of Aboriginal and Torres Strait Islander people:

  • constant levels of migration as observed in the 2016 Census based on address 5 years ago.
     

Trends in interstate migration

The 'place of usual residence five years ago' Census questions shows that the number of Aboriginal and Torres Strait Islander people who changed their state or territory of usual residence between:

  • 2011 and 2016 was 25,960
  • 2006 and 2011 was 21,340
  • 2001 and 2006 was 18,440.
     

This measure was unable to account for:

  • Aboriginal and Torres Strait Islander children under five years of age on Census night
  • people whose place of residence five years ago was overseas
  • people whose state or territory of usual residence five years ago was not recorded.
     

In addition, Aboriginal and Torres Strait Islander people overseas on Census night were not counted in the Census. 

Table 13 - Interstate arrivals and departures(a)(b), 2011 to 2016
 State/territory of arrival
State/territory of departureNSWVic.QldSAWATas.NTACTTotal departures(c)
NSW. .1,6025,3904236642104107069,413
Vic.1,162. .958289335191248773,261
Qld3,7421,202. .4291,1163631,0653378,254
SA343332430. .29947376231,851
WA591382833282. .168499382,793
Tas.22032847562191. .41181,335
NT4623811,40566564279. .1043,736
ACT62910621111451836. .1,056
Total arrivals (c)7,1664,3329,7062,1663,2991,0762,6741,30731,735
Net movements-2,2471,0711,452315506-259-1,062251. .

. . not applicable
a. Aboriginal and Torres Strait Islander children under five years of age on Census night were excluded, as were people whose place of usual residence five years ago was overseas or was not recorded.
b. Data is adjusted to account for Census net undercount and records for which Indigenous status was not stated. See section: Method used to produce interstate migration assumption.
c. Includes Other Territories.
Note: Totals and components may not be consistent within and between tables due to introduced random error to protect confidentiality of Census respondents – see Census Dictionary, 2016 (cat. no. 2901.0).

Method used to produce interstate migration assumption

State or territory of usual residence on Census night was cross-tabulated with state or territory of usual residence five years ago to obtain net intestate migration for each state and territory for 2011 to 2016.

These figures are affected by a number of data quality issues, including Census net undercount and records for which Indigenous status was not stated. To account for these, net interstate migration estimates were adjusted by a proportion calculated by dividing Aboriginal and Torres Strait Islander ERP by Aboriginal and Torres Strait Islander Census counts, for each state and territory.

The adjusted net interstate migration estimates were then divided by five to obtain annual movements, which were assumed to remain constant over the projection period. In addition, they were used as constraints on migration assumptions for Indigenous Regions and Remoteness Areas.

Table 14 - Assumed net interstate migration
 NSWVic.QldSAWATas.NTACT
Annual net migration-45221429162100-52-21350

Note: Totals and components may not be consistent within and between tables due to introduced random error to protect confidentiality of Census respondents – see Census Dictionary, 2016 (cat. no. 2901.0).

Age/sex profile of interstate migration

The age/sex profile of intestate migration was derived from the 'place of usual residence one year ago' question from the 2016 Census. Arrival and departure rates for the states and territories were calculated by single year of age and sex and adjustments were made where appropriate to ensure the age/sex profiles of projected populations were plausible. All age/sex arrival and departure disaggregations were constrained by the net internal migration assumption at the state/territory level. 

Indigenous Regions migration

Annual net migration estimates for each IREG were calculated in the same way as for the states and territories, and were assumed to remain constant over the 15-year projection period.

Table 15 - Assumed net internal migration, Indigenous Regions
Indigenous RegionAnnual net migration
Dubbo-113
North-Eastern NSW-85
North-Western NSW-142
NSW Central and North Coast236
Riverina - Orange-34
South-Eastern NSW22
Sydney - Wollongong-336
Melbourne136
Victoria exc. Melbourne78
Brisbane606
Cairns - Atherton-44
Cape York-60
Mount Isa-163
Rockhampton-22
Toowoomba - Roma-29
Torres Strait-92
Townsville - Mackay95
Adelaide138
Port Augusta-50
Port Lincoln - Ceduna-26
Broome-7
Geraldton-38
Kalgoorlie21
Kununurra-74
Perth126
South Hedland33
South-Western WA53
West Kimberly-14
Tasmania-52
Alice Springs-5
Apatula-28
Darwin-89
Jabiru - Tiwi62
Katherine-225
Nhulunbuy101
Tennant Creek-29
Australian Capital Territory50

Remoteness Areas migration

Annual net migration estimates for each Remoteness Area were calculated in the same way as for states and territories, and were assumed to remain constant over the 15-year projection period. 

Table 16 - Assumed net internal migration, Remoteness Areas
Remoteness AreaAnnual net migration
Major Cities917
Inner and Outer Regional73
Remote and Very Remote-990

Overseas migration assumption

One assumption has been made for future net overseas migration of Aboriginal and Torres Strait Islander people:

  • zero overseas migration, with zero arrivals and zero departures.
     

Trends in overseas migration

According to the 2016 Census there were 1,969 Aboriginal and Torres Strait Islander people resident in Australia in 2016 who lived overseas in 2011. Slightly fewer numbers of Aboriginal and Torres Strait Islander people resident in 2011 also lived overseas in 2006 (1,375 persons). 

This level of in-migration has a negligible effect on the size of the future Aboriginal and Torres Strait Islander population. In addition, there will also be some level of out-migration leading to an even smaller net migration rate.

Unexplained growth assumption

Zero unexplained growth has been assumed for this series of projections.

Australia

Size and growth

In 2016, there were 798,400 Aboriginal and Torres Strait Islander people, representing 3.3% of the total Australian population. Between 2006 and 2016, the Aboriginal and Torres Strait Islander population increased by 2.2% (from 640,000 people) per year on average, compared with 1.6% for the total Australian population.

By 2031, the Aboriginal and Torres Strait Islander population is projected to increase to between 1,046,000 people (low series) and 1,093,000 people (high series) at an average annual growth rate of between 1.8% and 2.1% per year. In comparison, the average annual growth rate of the total Australian population is projected to be between 1.3% and 1.7% per year over the same period (Population Projections, Australia, 2017 (base) to 2066).

The Aboriginal and Torres Strait Islander population of Australia is projected to reach one million people by 2027 (high series) and by 2029 (low series).

Natural increase

At the national level any growth in the Aboriginal and Torres Strait Islander population is entirely due to natural increase as net overseas migration is assumed to be zero.

Although decreasing fertility rates are assumed, the number of Aboriginal and Torres Strait Islander births is projected to increase over the projection period. This is due to the increase in the number of women of child-bearing ages over the projection period as well as the assumption of increasing paternity rates.

As a result:

  • births are projected to increase from 18,970 in 2017 (Series B), to between 22,090 and 27,970 in 2031
  • deaths are projected to increase from 3,620 in 2017 (Series B), to between 4,250 and 5,030 in 2031
  • natural increase remains consistently high, increasing from 15,350 in 2017 (Series B) to between 17,060 and 23,720 in 2031.
     

Population structure

Table 17 - Estimated and projected Aboriginal and Torres Strait Islander population(a)(b), by age group, Australia, at 30 June
Age group (years)200620162031 (series A)2031 (series B)2031 (series C)
Number
0–14242,772274,333350,185324,885309,154
15–24115,425155,179186,946186,912186,843
25–3490,433113,812165,804165,695165,508
35–4485,14487,782133,262133,087132,789
45–5458,34280,46289,49989,27288,904
55–6429,74952,78580,43180,03079,450
65–7412,64224,29356,47755,91955,103
75 and over5,5299,71930,40429,43628,242
Total640,036798,3651,093,0081,065,2361,045,993
Proportion
0–1437.934.432.030.529.6
15–2418.019.417.117.517.9
25–3414.114.315.215.615.8
35–4413.311.012.212.512.7
45–549.110.18.28.48.5
55–644.66.67.47.57.6
65–742.03.05.25.25.3
75 and over0.91.22.82.82.7
Total100.0100.0100.0100.0100.0

a. Estimates and projections based on the 2016 Census.
b. Due to rounding, proportions may not add to 100%.

The Aboriginal and Torres Strait Islander population has a relatively young age structure with a median age of 22.9 years in 2016 (37.8 years for the Non-Indigenous population).

  • in 2006 the median age was 21.2 years
  • by 2031 the median age is projected to be between 25.5 and 26.5 years.


The Aboriginal and Torres Strait Islander population is projected to increase across all age groups between 2016 and 2031.

    People aged 0–14 years

    The number of children (0–14 years) is 274,300 in 2016. This is projected to:

    • increase to between 309,200 and 350,200 in 2031
    • decrease as a proportion of the population, from 34.4% in 2016 to between 29.6% and 32.0% in 2031.
       

    People aged 15–64 years

    The number of people aged 15–64 years is 490,000 in 2016. This is projected to:

    • increase to between 653,500 and 655,900 in 2031
    • remain stable as a proportion of the population, from 61.4% in 2016 to between 60.0% and 62.5% in 2031.
       

    People aged 65 years and over

    The number of people aged 65 years and over is 34,000 in 2016. This is projected to:

    • increase to between 83,300 and 86,900 in 2031
    • increase as a proportion of the population, from 4.3% in 2016 to between 7.9% and 8.0% in 2031.
       

    States and territories

    All three series project continuing growth for the Aboriginal and Torres Strait Islander population for all states and territories between 2016 and 2031.

    The Aboriginal and Torres Strait Islander population of the Australian Capital Territory is projected to be the fastest growing of all states and territories, with an average annual growth rate of between 2.6% and 2.9% per year. This is followed by:

    • Victoria (between 2.4% and 2.7%)
    • Queensland (between 2.1% and 2.4%)
    • Tasmania (between 1.5% and 1.8%).
       

    These high rates of population growth in these states and territories are in part due to:

    • relatively large cohorts of Aboriginal and Torres Strait Islander people moving into peak child-bearing ages throughout the projection period
    • the assumption of increasing paternity rates
    • the assumed net interstate migration in some cases, notably for Queensland (a gain of 291 people per year) and Victoria (a gain of 214 people per year).
       

    The Aboriginal and Torres Strait Islander population of New South Wales is projected to grow between 1.8% and 2.1% per year on average. This lower rate of growth is due to the assumed net migration loss of 452 people per year.

    The Northern Territory is projected to have the lowest average annual growth rate over the projection period, of between 0.8% and 1.0% per year.

    This is in part due to the age structure of the Northern Territory population which, unlike many of the other states and territories, is relatively stable. The absolute size of the Aboriginal and Torres Strait Islander population in child-bearing age groups (15-49 years) therefore increases relatively consistently throughout the projection period. As a result, projected numbers of births in the Northern Territory do not increase as rapidly as in other states and territories, and therefore population growth is slower. In addition, the projected Aboriginal and Torres Strait Islander population in the Northern Territory is largely unaffected by an increasing paternity assumption as the Territory has the lowest proportion of children born to Aboriginal and Torres Strait Islander fathers and non-Indigenous mothers.

    With relatively stable age structures, lower average annual growth rates are also projected for:

    • Western Australia (between 1.7% and 2.0%)
    • South Australia (between 1.8% and 2.1%).
       

    Assumed net interstate migration for Western Australia (a gain of 100 people per year) and South Australia (a gain of 62 people per year) has a small positive effect on the rate of population growth over the projection period.

    Components of population change for Australia and each state and territory are presented in data cubes attached to this release on the ABS website.

    Table 18 - Estimated and projected Aboriginal and Torres Strait Islander population(a), states and territories, 2016 - 2031
     200620162031 SERIES A2031 SERIES B2031 SERIES C
     no.no.no.Growth rate (%)(b)no.Growth rate (%)(b)no.Growth rate (%)(b)
    NSW207,786265,685363,3542.1353,6671.9346,8041.8
    Vic.48,09357,76786,2972.783,9662.582,2662.4
    Qld175,267221,276315,5852.4307,5472.2302,0932.1
    SA34,68142,26557,5512.156,1001.955,1161.8
    WA83,130100,512134,6272.0131,3611.8129,2071.7
    Tas.22,88128,53737,2531.836,3071.635,5871.5
    NT61,68674,54686,4351.084,6830.983,5450.8
    ACT6,2747,51311,5812.911,2852.711,0592.6
    Aust.(c)640,036798,3651,093,0082.11,065,2361.91,045,9931.8

    a. Estimates and projections based on the 2016 Census.
    b. Average annual growth rate for the period 2016 to 2031.
    c. Includes Other Territories.

    Changing state/territory share

    New South Wales is projected to continue to have the largest share of the Aboriginal and Torres Strait Islander population. The population in New South Wales is projected to remain stable at 33% in both 2016 and 2031.

    • Queensland's share is projected to increase from 27.7% in 2016 to 28.9% in 2031
    • Victoria's share is projected to increase from 7.2% in 2016 to 7.9% in 2031
    • ACT's share is projected to increase from 0.9% in 2016 to 1.1% in 2031
    • Northern Territory is the only jurisdiction whose share is projected to decline, from 9.3% in 2016 to 7.9% in 2031.
       

    The distribution amongst the remaining states and territories is projected to remain largely unchanged over the projection period.

    Table 19 - Projected distribution of Aboriginal and Torres Strait Islander population(a)(b), states and territories, at 30 June
     20162031 (series A)2031 (series B)2031 (series C)
     %%%%
    NSW33.333.233.233.2
    Vic.7.27.97.97.9
    Qld27.728.928.928.9
    SA5.35.35.35.3
    WA12.612.312.312.4
    Tas.3.63.43.43.4
    NT9.37.97.98.0
    ACT0.91.11.11.1
    Aust.(c)100.0100.0100.0100.0

    a. Estimates and projections based on the 2016 Census.
    b. Due to rounding, proportions may not add to 100%.
    c. Includes Other Territories.

    Remoteness Areas and Indigenous Regions

    In 2016, there were 298,400 Aboriginal and Torres Strait Islander people residing in Major Cities, followed by 351,200 in Inner and Outer Regional areas and 148,700 in Remote and Very Remote areas.

    By 2031, the Aboriginal and Torres Strait Islander population is projected to increase to between:

    • 421,200 people (low series) and 440,700 people (high series) in Major Cities, at an average annual growth rate of between 2.3% and 2.6% per year
    • 463,800 people (low series) and 485,000 people (high series) in Inner and Outer Regional areas, at an average annual growth rate of between 1.9% and 2.2% per year
    • 161,100 people (low series) and 167,300 people (high series) in Remote and Very Remote areas, at an average annual growth rate of between 0.5% and 0.8% per year.
       
    Table 20 - Estimated and projected Aboriginal and Torres Strait Islander population(a), Remoteness Areas, 2006 - 2031
     200620162031 (series A)2031 (series B)2031 (series C)
    Remoteness Areano.no.no.Growth rate (%)(b)no.Growth rate (%)(b)no.Growth rate (%)(b)
    Major Cities242,987298,430440,6702.6429,2562.5421,1632.3
    Inner and Outer Regional280,477351,206485,0492.2472,4902.0463,7681.9
    Remote and Very Remote116,572148,729167,2890.8163,4900.6161,0620.5
    Australia(c)640,036798,3651,093,0082.11,065,2361.91,045,9931.8

    a. Estimates and projections based on the 2016 Census.
    b. Average annual growth rate for the period 2016 to 2031.
    c. Includes Other Territories.

    Population share

    Based on all three series:

    • Inner and Outer Regional areas are projected to continue to have the largest Aboriginal and Torres Strait Islander population with their share remaining stable at 44% in both 2016 and 2031
    • Major Cities share is projected to increase from 37% in 2016 to 40% in 2031
    • Remote and Very Remote areas share is projected to decrease from 19% in 2016 to 15% in 2031.
       

    Indigenous Regions

    All three series project continuing population growth in the majority of Indigenous Regions between 2016 and 2031:

    The Aboriginal and Torres Strait Islander population in Brisbane is projected to be the fastest growing of all Indigenous regions, with an average annual growth rate of between 2.7% and 3.0% per year. This is followed by:

    • Australian Capital Territory (between 2.6% and 2.9%)
    • Victoria, excluding Melbourne (between 2.5% and 2.8%).
       

    Katherine is the only Indigenous region where the Aboriginal and Torres Strait Islander population is projected to decrease between 2016 and 2031. This can be attributed to assumed net migration loss (see section Assumptions, Table 15).

    Table 21 - Estimated and projected Aboriginal and Torres Strait Islander population(a), Indigenous Regions, 2016 - 2031
     20162031 (series A)2031 (series B)2031 (series C)
    Indigenous Regionno.no.Growth rate (%)(b)no.Growth rate (%)(b)no.Growth rate (%)(b)
    Dubbo15,96220,4711.719,9111.519,5071.3
    North-Eastern NSW25,47533,6251.932,7311.732,0961.6
    North-Western NSW9,84810,8190.610,5220.410,3000.3
    NSW Central and North Coast85,169123,2932.5119,9962.3117,6542.2
    Riverina - Orange30,83043,3152.342,1122.141,2782.0
    South-Eastern NSW16,71623,3552.322,7502.122,3131.9
    Sydney - Wollongong81,685108,4761.9105,6451.7103,6561.6
    Melbourne28,58442,0422.641,0112.440,2492.3
    Victoria exc. Melbourne29,18344,2552.842,9552.642,0172.5
    Brisbane84,454131,0783.0127,8462.8125,4892.7
    Cairns - Atherton30,05040,5112.039,4661.838,7941.7
    Cape York10,57913,9831.913,6131.713,3351.6
    Mount Isa9,0039,6090.49,3280.29,1590.1
    Rockhampton26,94136,8082.135,8701.935,2761.8
    Toowoomba - Roma21,35028,6122.027,8861.827,4321.7
    Torres Strait7,4038,4790.98,2480.78,1020.6
    Townsville - Mackay31,49646,5052.645,2902.544,5062.3
    Adelaide30,12443,7452.542,6272.341,8552.2
    Port Augusta9,40310,9711.010,6950.910,5300.8
    Port Lincoln - Ceduna2,7382,8350.22,7780.12,7310.0
    Broome6,0577,7091.67,5261.57,3961.3
    Geraldton8,50210,0571.19,7920.99,6180.8
    Kalgoorlie7,5109,9331.99,7041.79,5521.6
    Kununurra6,0406,7590.86,5560.56,4430.4
    Perth38,91956,2602.554,8932.353,9472.2
    South Hedland11,80015,8142.015,4441.815,2101.7
    South-Western WA15,63120,5171.820,0561.719,7631.6
    West Kimberly6,0537,5781.57,3901.37,2781.2
    Tasmania28,53737,2531.836,3071.635,5871.5
    Alice Springs6,8077,2860.57,1310.37,0330.2
    Apatula10,19112,0251.111,7601.011,5870.9
    Darwin18,30921,1661.020,7210.820,3970.7
    Jabiru - Tiwi12,42516,0371.715,7421.615,5631.5
    Katherine11,0639,609-0.99,435-1.19,290-1.2
    Nhulunbuy11,37715,7102.215,3672.015,2172.0
    Tennant Creek4,3744,6020.34,5270.24,4580.1
    Australian Capital Territory7,51311,5812.911,2852.711,0592.6
    Australia(c)798,3651,093,0082.11,065,2361.91,045,9931.8

    a. Estimate and projections based on the 2016 Census.
    b. Average annual growth rate for the period 2016 to 2031.
    c. Includes Other Territories.

    Sensitivity to projection assumptions

    This section discusses the effect of differing levels of components of population change on the projected size, structure and numbers of births and deaths of Aboriginal and Torres Strait Islander Australians. Overall, sensitivity analysis shows that varying the assumptions appears to have a minimal effect on the size of the projected Aboriginal and Torres Strait Islander population.

    Fertility rates

    Sensitivity analysis was undertaken into the effect of fertility assumptions on the size of the future Aboriginal and Torres Strait Islander population and the number of projected births. The below table shows the projected Aboriginal and Torres Strait population and births in 2031 under three fertility assumptions:

    Based on the Series B fertility assumption (1.0% annual decline in fertility rates):

    • Aboriginal and Torres Strait Islander population of Australia is projected to reach 1,065,200 people in 2031 (up from 798,400 in Series B in 2016)
    • births are projected to increase from 18,970 in 2017 to 24,310 in 2031.
       

    Assuming fertility rates remain constant (Series D) it is projected that:

    • Aboriginal and Torres Strait Islander population of Australia will reach 1,081,900 people in 2031 (up from 1,065,200 in Series B in 2031)
    • births will be higher than in Series B in 2031 (26,660 compared with 24,310)
    • this will result in more Aboriginal and Torres Strait Islander children aged 0-14 years in 2031 than in Series B (341,600 compared with 324,900).
       

    Assuming a 1.5% annual decline in fertility rates (Series E):

    • Aboriginal and Torres Strait Islander population of Australia is projected to reach 1,057,400 people in 2031 (down from 1,065,200 people in Series B in 2031)
    • births will be lower than in Series B in 2031 (23,250 compared with 24,310 )
    • this will result in fewer Aboriginal and Torres Strait Islander children aged 0-14 years in 2031 than in Series B (317,100 compared with 324,900).
       
    Table 22 - Estimated and projected Aboriginal and Torres Strait Islander population and births(a), alternative fertility assumptions
      NSWVic.QldSAWATas.NTACTAust. (b)
    POPULATION ('000)
    2016 265.757.8221.342.3100.528.574.57.5798.4
    2031          
     Constant (series D)359.185.1312.657.0133.636.786.011.41,081.9
     1.0% annual decrease (series B)353.784.0307.556.1131.436.384.711.31,065.2
     1.5% annual decrease (series E)351.183.4305.255.7130.336.184.111.21,057.4
    BIRTHS
    2017(c) 6,5101,4475,4399962,3316301,42718118,965
    2031          
     Constant (series D)9,3172,3137,9381,3603,0848721,47429226,656
     1.0% annual decrease (series B)8,5452,1447,2231,2382,7678111,30127424,309
     1.5% annual decrease (series E)8,1952,0686,8971,1822,6257851,22326623,246

    a. Assumptions relating to Aboriginal and Torres Strait Islander paternity rates, life expectancy at birth and interstate migration are at levels specified for Series B.
    b. Includes Other Territories.
    c. Number of births projected under Series B.

    Paternity rates

    Sensitivity analysis was undertaken into the effect of paternity assumptions on the size of the future Aboriginal and Torres Strait Islander population and the number of projected births.

    The below table shows the projected Aboriginal and Torres Strait population and births in 2031 under the three paternity assumptions:

    Based on the Series B paternity assumption (1.0% annual increase in paternity rates):

    • Aboriginal and Torres Strait Islander population of Australia is projected to reach 1,065,200 people in 2031 (up from 798,400 in 2016)
    • births are projected to increase from 18,970 in 2017 to 24,310 in 2031.


    Assuming paternity rates remain constant (Series F) it is projected that:

    • Aboriginal and Torres Strait Islander population of Australia will reach 1,057,600 people in 2031 (down from 1,065,200 in Series B in 2031)
    • births will be lower than in Series B in 2031 (23,170 births compared with 24,310)
    • This will result in fewer Aboriginal and Torres Strait Islander children aged 0-14 years in 2031 than in Series B (317,200 compared with 324,900).


    Assuming a 2.0% annual increase in paternity rates (Series G):

    • Aboriginal and Torres Strait Islander population of Australia is projected to reach 1,073,600 people in 2031 (up from 1,065,200 people in Series B in 2031)
    • births will be higher than in Series B in 2031 (25,610 births compared with 24,310)
    • This will result in more Aboriginal and Torres Strait Islander children aged 0-14 years in 2031 than in Series B (333,300 compared with 324,900).
       
    Table 23 - Estimated and projected Aboriginal and Torres Strait Islander population and births(a), alternative paternity assumptions
      NSWVic.QldSAWATas.NTACTAust. (b)
    POPULATION ('000)
    2016 265.757.8221.342.3100.528.574.57.5798.4
    2031          
     Constant (series F)350.683.1305.455.7130.736.084.511.21,057.6
     1.0% annual increase (series B)353.784.0307.556.1131.436.384.711.31,065.2
     2.0% annual increase (series G)357.084.9309.956.5132.036.784.811.41,073.6
    BIRTHS
    2017(c) 6,5101,4475,4399962,3316301,42718118,965
    2031          
     Constant (series F)8,0952,0096,9031,1822,6807581,28025423,167
     1.0% annual decrease (series B)8,5452,1447,2231,2382,7678111,30127424,309
     2.0% annual increase (series G)9,0552,2997,5831,3032,8678731,32529725,608

    a. Assumptions relating to Aboriginal and Torres Strait Islander fertility rates, life expectancy at birth and interstate migration are at levels specified for Series B.
    b. Includes Other Territories.
    c. Number of births projected under Series B.

    Life expectancy at birth

    Sensitivity analysis was undertaken into the effect of life expectancy at birth assumptions on the size of the future Aboriginal and Torres Strait Islander population and the number of projected deaths.

    The below table shows the projected Aboriginal and Torres Strait population and deaths in 2031 under the three life expectancy at birth assumptions:

    Based on the series B life expectancy assumption (annual increase of 0.40 years for males and 0.25 years for females):

    • Aboriginal and Torres Strait Islander population of Australia is projected to reach 1,065,200 people in 2031 (up from 798,400 in 2016)
    • deaths are projected to increase from 3,620 in 2017 to 4,570 in 2031.
       

    Assuming an annual increase of 0.25 years for males and 0.20 years for females (series I) it is projected that:

    • Aboriginal and Torres Strait Islander population of Australia will reach 1,061,400 people in 2031 (down from 1,065,200 in Series B in 2031)
    • deaths are projected to be higher than in Series B in 2031 (5,040 deaths compared with 4,570).
       

    Assuming an annual increase of 0.45 years for males and 0.35 years for females (series H):

    • Aboriginal and Torres Strait Islander population of Australia is projected to reach 1,067,900 people in 2031 (up from 1,065,200 in Series B in 2031)
    • deaths are projected to be lower than in Series B in 2031 (4,230 deaths compared with 4,570).
       
    Table 24 - Estimated and projected Aboriginal and Torres Strait Islander population and deaths(a), alternative life expectancy at birth assumptions
      NSWVic.QldSAWATas.NTACTAust. (b)
    POPULATION ('000)
    2016 265.757.8221.342.3100.528.574.57.5798.4
    2031          
     Annual increase of 0.25 years for males and 0.20 years for females (series I)352.483.7306.655.9130.936.184.311.31,061.4
     Annual increase of 0.40 years for males and 0.25 years for females (series B)353.784.0307.556.1131.436.384.711.31,065.2
     Annual increase of 0.45 years for males and 0.35 years for females (series H)354.684.2308.256.3131.736.485.011.31,067.9
    DEATHS
    2017(c) 1,157263798238541142453223,616
    2031          
     Annual increase of 0.25 years for males and 0.20 years for females (series I)1,6043521,191316766193579385,041
     Annual increase of 0.40 years for males and 0.25 years for females (series B)1,4493171,067292704173529334,566
     Annual increase of 0.45 years for males and 0.35 years for females (series H)1,337294978273660160497314,232

    a. Assumptions relating to Aboriginal and Torres Strait Islander fertility rates, life expectancy at birth and interstate migration are at levels specified for Series B.
    b. Includes Other Territories.
    c. Number of deaths projected under Series B.

    Interstate migration

    One assumption has been made for future net internal migration of Aboriginal and Torres Strait Islander people:

    • constant levels of migration as observed in the 2016 Census of Population and Housing based on address 5 years ago.
       

    Guide to using historical estimates for comparative analysis and reporting

    Outlined below are issues to consider in choosing an appropriate series of Aboriginal and Torres Strait Islander population estimates, for the purpose of analysing or reporting on this population over time.

    Why the ABS recasts Aboriginal and Torres Strait Islander population estimates after each Census

    The Census of Population and Housing (Census) provides the basis of Australia's official population estimates. For the total Australian population, quarterly estimates can be produced between Censuses by applying components of population growth (births, deaths and migration) to the latest Census-based estimate. Generally speaking, the accuracy of the Census and component data means that only minor adjustments to the population figures occur after each Census.

    However, Aboriginal and Torres Strait Islander Census counts and the quality of data on births, deaths and migration of Aboriginal and Torres Strait Islander people do not support the use of the standard approach to population estimation. Instead, the ABS uses assumptions about future fertility, paternity, life expectancy and migration to project figures out from each Census. At the same time, it is also necessary to backcast the Aboriginal and Torres Strait Islander population, because each Census count is sufficiently different from the last, due to a range of non-demographic factors, such as changing levels of self identification in the Census.

    The uncertainty in the Census and component data occurs because:

    • Aboriginal and Torres Strait Islander population is very small compared with the total Australian population (around 3.3%), and
    • Aboriginal and Torres Strait Islander population requires people not only to be counted in the Census and component datasets, but also to be identified as being of Aboriginal or Torres Strait Islander origin.
       

    The differences between the Aboriginal and Torres Strait Islander population estimates derived from each Census thus tend to be larger than demographic changes can account for. Each Census-based estimate reflects both the desire of people at that time to be identified as being of Aboriginal or Torres Strait Islander origin, and the ability at that time for the information to be effectively collected in the Census.

    The Australian Census Longitudinal Dataset (ACLD) suggests that a certain proportion of the population will be counted as Aboriginal or Torres Strait Islander in one Census, but as non-Indigenous in the next, and vice versa – see Census of Population and Housing: Understanding the Increase in Aboriginal and Torres Strait Islander Counts for further information.

    Graph 8, below, shows the percentage increase in estimated resident population (ERP) between Censuses for both the Aboriginal and Torres Strait Islander population and the total Australian population, for the last five intercensal periods. The change in the total population between Censuses remains lower than 10%, and is largely consistent with birth, death and migration rates observed between Censuses. This is not the case for the Aboriginal and Torres Strait Islander population, for which implausible demographic trends would need to have occurred to account for the intercensal difference.

    Between 2011 and 2016, the Aboriginal and Torres Strait Islander Census counts increased by 18.4% (100,800 persons). Of this increase:

    • 78.6% can be accounted for by explainable demographic factors of population changes - that is, births, deaths and migration
    • propensity to identify was a major contributor to the remaining 21.4% increase, not due to demographic factors.
       

    For more information see Census of Population and Housing: Understanding the Increase in Aboriginal and Torres Strait Islander Counts and Occasional Paper: Population Issues, Indigenous Australians (cat. no. 4708.0)

    Other collections, such as surveys and administrative datasets also rely on a person's Indigenous status to be accurately reported and recorded, and therefore may likewise be susceptible to differing rates of identification, which may also vary over time. The changing rates of identification of Aboriginal and Torres Strait Islander people in the Census and other datasets create challenges when comparing data about this population over time. For further information, see Information Paper: Perspectives on Aboriginal and Torres Strait Islander Identification in Selected Data Collection Contexts (cat. no. 4726.0) for further information.

    Comparison of historical series

    After each Census, the ABS creates a time series for the population based on that Census count, by projecting and backcasting around this estimate. The backcast series shows what the Aboriginal and Torres Strait Islander population (based on the latest Census) would have been in previous periods, based purely on demographic change. Similarly, the projected series shows how the currently identified Aboriginal and Torres Strait Islander population may change in future years, if certain demographic assumptions were to hold. Each Census-based series is independent from the others.

    Graph 9 shows the five different population series that cover the period 1996 to 2016, as well as how each year's estimated population would change if a simple, straight line interpolation was applied between successive Census-based estimates.


    Often, population estimates for Aboriginal and Torres Strait Islander people are used as the denominator for rates, to compare data for the Aboriginal and Torres Strait Islanders population with the non-Indigenous population, or to create time-series indicators about how various aspects of the well-being of Aboriginal and Torres Strait Islander people are changing over time. The use of different series of population estimates shown in graph 9 will clearly impact on such indicators.

    Following are some examples of the impact that the choice of Aboriginal and Torres Strait Islander population estimates can have on a rate. The examples use six different series to demonstrate this:

    • the 2016 Census-based series
    • the 2011 Census-based series
    • the 2006 Census-based series
    • a series which uses each Census-based series for the two years before and after that Census (option 1)
    • a series which transitions between Census-based series in a way that minimises the 'jump' in the transition year (option 2)
    • linear interpolation between Census estimates.
       

    Example 1 - Child mortality rates

    The use of different Census-based Aboriginal and Torres Strait Islander population estimates, while showing a similar pattern of change over time, has a considerable impact on the level of historical child mortality rates, as shown in graph 10. When using a combination of series, as shown in graph 11, the downward trend in the rate is more obvious.

    1. Rates are for total population of NSW, QLD, WA, SA and NT.
    2. Uses five-year average deaths, and population for the middle year of the five-year period.
    3. Projected data is based on series B.
       
    1. Rates are for total population of NSW, QLD, WA, SA and NT. 
    2. Uses five-year average deaths, and population for the middle year of the five-year period.
    3. Option 2 uses the 2011 Census-based estimate for 2008 to 2012, and the 2016 Census-based estimate for 2013 onwards.
       

    Example 2 - School enrolments

    In the case of school enrolments data, the use of previous Census-based series generates impossible results, with rates exceeding 100%. In contrast, when using a combination of Census-based population series (graph 13), the enrolment rates remain plausible throughout, although there is no longer a clear trend in the time-series. Further analysis would be needed to determine the most appropriate choice of Aboriginal and Torres Strait Islander population estimates. In particular, the choice may depend on an understanding of how identification rates in the enrolment data (numerator) had changed over time.

    1. Option 2 uses the 2006 Census-based estimate for 2006 and 2007, the 2011 Census-based estimate for 2008 to 2012, and the 2016 Census-based estimate for 2013 onwards.

       

    Example 3 - Standardised death rates

    In the case of age-standardised death rates, the use of different Aboriginal and Torres Strait Islander population estimates changes the direction of the trend.

    1. Rates are for total population of NSW, QLD, WA, SA and NT.
    2. Uses five-year average deaths, and population for the middle year of the five-year period.
    3. Projected data is based on series B (high projection for 2006-based).
       
    1. Rates are from total population of NSW, QLD, WA, SA and NT.
    2. Uses five-year average deaths, and population for the middle year of the five-year period.
    3. Option 2 uses the 2011 Census-based estimate for 2008 to 2012, and the 2016 Census-based estimate for 2013 onwards.
       


    In each of the examples above, of the three methods of transition between population estimate series shown, the time-series rate is smoothest when using a linear interpolation between Census year estimates. Changing from one Census-based series to the next results in a sharp drop in the rate at the changeover point. This can be seen at points 2009, 2013 and 2014. 2018 would be the equivalent 'decision point' for the current intercensal period. The extent of the 2018 transition will not be known until after the 2021 Census-based ERP series becomes available.

    Which series to use

    The question of which historical population series to use depends on the purposes of the analysis. The following provides guidelines to help in making these decisions.

    The 2016-based series is the most accurate and up-to-date series currently produced by the ABS, including in terms of the methodology used in the Census collection and in the estimation/projection processes. The 2016-based series can generally be used for any of the following scenarios:

    • for demographic analysis of the Aboriginal and Torres Strait Islander population
    • for forward-looking analysis (i.e. from 2016 onwards), for any purpose
    • as the denominator of rates being compared over time, if:
    • the time series is short, generally no further back than the penultimate (2011) Census
    • the numerator data are known to have been fairly consistently high over time
    • analysis is restricted to remote geographies, where the impact of increased identification is much lower than in non-remote areas
    • when there is a known quality issue in the data from earlier Censuses.
       

    Using a range of different Census-based population estimate series could be considered when:

    • transitioning from one series to the next will maximise consistency of identification levels and coverage between the numerator and the denominator
    • historical rates are thought to be artificially deflated when using the 2016-based population estimates (usually due to lower identification rates in the numerator series in earlier years)
    • there is a known relationship between identification in the numerator data and the Census data. Data linkage may be used to inform on this relationship – for example see Linking Death registrations to the 2016 Census. This relationship may be applied to the 2016-based series as a factor, or be used to inform the choice of a transitional series
    • data confrontation using supplementary data sources indicates that the 2016-based population estimates do not produce a plausible result.
       

    In some cases, an alternative data source may exist which is more comparable/consistent with the numerator data, and could be used rather than a population estimate series. For example,

    If in any doubt, the ABS recommends that data users conduct their own analysis, for example similar to that illustrated in the examples above. This will highlight the impact of non-demographic changes on their particular area of interest.

    Impact of future changes

    A new series for Aboriginal and Torres Strait Islander population estimates will be produced following the 2021 Census. Depending on how the 2021 Census-based estimate compares with the 2016 Census-based estimate, current indicator trends may change as a result of rebasing any population estimates to the new Census.

    Aboriginal and Torres Strait Islander population projections are produced to illustrate potential future demographic changes to the currently identified population. The 2016-based projections therefore do not include any assumption variable on propensity to identify. Anyone considering the future population should consider their requirements for a projection based on a change in propensity to identify, and note that the ABS projections cannot be used for this purpose.

    Backcast estimates for the period 2006 to 2015

    Backcast estimates included in this release are compiled using the 30 June 2016 estimates of the Aboriginal and Torres Strait Islander population as the base population and assumptions on mortality and interstate migration.

    A single time series of Aboriginal and Torres Strait islander population estimates for the period 2006 to 2015 has been produced using the following assumptions:

    • 2011 to 2016: life expectancy at birth increases by 0.40 years per year for males and 0.25 years per year for females
    • 2006 to 2011: life expectancy at birth increases by 0.30 years per year for males and 0.20 years per year for females
    • Net interstate migration assumptions for each of the two intercensal periods will be based on levels observed in each respective intercensal period
    • Zero net overseas migration occurred across the entire series with no arrivals and departures.
       

    There were 798,400 Aboriginal and Torres Strait Islander people in 2016 based on the 2016 Census. Backcast estimates of the Aboriginal and Torres Strait Islander population was 640,000 in 2006. Between 2006 and 2016, the Aboriginal and Torres Strait Islander population increased by 2.2% per year on average.

    Table 25 - Estimates of Aboriginal and Torres Strait Islander Australians(a), states/territories, at 30 June
     2006200720082009201020112012201320142015
    NSW207,786213,649219,394221,529230,865236,637242,442248,260253,891259,711
    Vic.48,09349,04850,03350,99451,94152,84853,74954,78855,77156,718
    Qld175,267179,993184,757189,488194,171198,776203,405207,979212,436216,969
    SA34,68135,44036,23436,99537,80538,60539,34440,11740,83641,554
    WA83,13084,93886,79288,63090,36792,09793,73195,41897,14098,825
    Tas.22,88123,46624,06224,67725,23225,75226,34726,87027,39927,955
    NT61,68662,96264,22565,54466,89468,23169,55670,85172,10073,365
    ACT6,2746,3966,5116,6356,7726,8947,0017,1387,2617,386
    Aust.(b)640,036656,133672,254688,340704,296720,093735,833751,680767,096782,745

    a. Estimates based on the 2016 Census.
    b. Includes Other Territories.

    Backcast estimates for the period 2001 to 2005

    Quality of backcast estimates for 2001 to 2005

    ABS advises that the 2001 to 2005 estimates included in the spreadsheet attached to this release should be used with caution.

    Reliable life expectancy estimates of the Aboriginal and Torres Strait Islander population are not available for the period 2001 to 2005. Therefore, mortality assumptions for these years were based on trends in life expectancy during 2005 to 2007 and 2015 to 2017. There will be a greater alignment between this assumption-based mortality and the actual mortality for the years closer to the base year than those for the out years.

    Moreover, estimates of the Aboriginal and Torres Strait Islander population at 30 June 2016 (based on the 2016 Census) are 19% larger than those at 30 June 2011 (based on the 2011 Census). As a consequence, the use of this 2016 ERP base introduces uncertainty to the historical estimates. The uncertainty increases as the time from the base year increases.

    Table 26 - Estimates of Aboriginal and Torres Strait Islander Australians(a), states/territories, at 30 June
     20012002200320042005
    NSW180,570186,018191,390196,790202,137
    Vic.43,29044,30645,27646,23747,124
    Qld154,166158,286162,454166,573170,858
    SA30,96731,71332,42033,14833,879
    WA74,06075,88177,65979,35381,123
    Tas.20,27120,78421,26121,78122,301
    NT56,14157,27058,39859,47660,565
    ACT5,5605,6975,8385,9806,123
    Aust.(b)565,242580,178594,922609,566624,341

    a. Estimates based on the 2016 Census.
    b. Includes Other Territories.

    Deriving non-Indigenous population estimates

    Context

    After each Census, the ABS produces estimates of the Aboriginal and Torres Strait Islander population for the Census year only by using information from the Census (together with some adjustments, the largest being for people missed in the Census). Using 2001 Census data, the ABS for the first time concurrently produced Aboriginal and Torres Strait Islander and non-Indigenous population estimates constrained to total population estimates for 30 June 2001. Accordingly, non-Indigenous population estimates correspond to the difference between the Aboriginal and Torres Strait Islander population estimates and the total population estimates. The ABS uses Census year estimates of the Aboriginal and Torres Strait Islander population and relevant assumptions on fertility, mortality and migration to compile backcast estimates and projections of this population group.

    Reliable data on births, deaths and migration of the Aboriginal and Torres Strait Islander population are not available for intercensal years. Due to this reason, it is not possible to produce credible annual estimates of the Aboriginal and Torres Strait Islander population and subsequently the non-Indigenous population for intercensal years using a components-based approach. However, the demand for such estimates, particularly as comparisons for measuring and monitoring differences between various Aboriginal and Torres Strait Islander and non-Indigenous rates, has substantially increased in recent years.

    This appendix discusses two options for deriving non-Indigenous population estimates for intercensal years, advantages and disadvantages of these options and then provides a recommendation about the optimal approach.

    Option 1

    Option 1 involves deriving non-Indigenous population estimates by subtracting Aboriginal and Torres Strait Islander backcast estimates and projections from the total Australian estimated resident population (ERP) for a given year. This option is currently being used for national reporting purposes. The advantages and disadvantages are covered below.

    Advantages:

    • This option uses the best available number for each population.
       

    Disadvantages:

    • A mixture of methods is being used - ERP for the total population and projections and backcast estimates for the Aboriginal and Torres Strait Islander population.
       

    Option 2

    Option 2 involves deriving non-Indigenous population estimates by subtracting Aboriginal and Torres Strait Islander backcast estimates and projections from total population projections. The advantages and disadvantages of this option are detailed below.

    Advantages:

    • The methods for calculating each population are comparable as both populations are projections
    • Both sets of projections are derived from the same base point and at approximately the same point in time.
       

    Disadvantages:

    • Both sets of projections are based on assumptions of future levels of fertility, mortality and migration (i.e. it is not measured data)
    • Non-Indigenous population is more likely to change demographically (through fluctuations in NOM) than the projections can effectively foresee.
       

    Impact on non-Indigenous mortality rates

    Non-Indigenous population estimates derived using Options 1 and 2 are used in calculating child (0-4 years) and age-standardised death rates for NSW, Qld, SA, WA, NT and the total of these five jurisdictions for the periods 2011 to 2015, 2012 to 2016 and 2013 to 2017. Method of calculation is the same as that used for the National Indigenous Reform Agreement (NIRA), National Healthcare Agreement (NHA) and Health Performance Framework (HPF) reporting (that is, the average of five years of deaths is divided by the mid-point population estimates and multiplied by 100,000). Results show that the difference between the rates based on non-Indigenous population derived using Option 1 and Option 2 is minimal (around 2%). This suggests that the non-Indigenous death rates are not particularly sensitive to the methods used in deriving non-Indigenous population estimates.

    Reccommendation

    The ABS consulted a number of expert stakeholders who agreed that Option 1 is the preferred method for deriving non-Indigenous population estimates (that is, by subtracting Aboriginal and Torres Strait Islander backcast estimates and projections from total population ERP). This option uses the best available number for each population and hence yields better quality estimates for non-Indigenous population. However, Option 1 cannot be used when total population ERP is not available (for example, when considering future trends). In such situations, Option 2 should be used.

    As with all advice the ABS provides, advice given in this article should be considered in relation to the specific requirements of data users and the appropriateness of the advice for their needs.

    Frequently asked questions

    What are Aboriginal and Torres Strait Islander population projections?

    Population projections illustrate how the Australian Aboriginal and Torres Strait Islander population would change in the future if specific patterns of fertility and paternity (births), mortality (deaths) and migration were to occur. These potential scenarios are based on assumptions regarding what could happen, based on recent demographic trends. As we cannot know what will happen in the future, a number of different assumptions are used to illustrate a range of possible outcomes. These outcomes include the level, growth, distribution and composition of the Aboriginal and Torres Strait Islander population.

    What are population projections used for?

    Population projections are used by governments, policy makers, planners, the private sector and others for a range of purposes such as policy design, policy implementation, performance reporting and service planning. They are commonly used to estimate future demand for products, services, infrastructure, energy, water and funding. For example, a high growth area with a young population may require investment in public transport, day care centres and schools. Aboriginal and Torres Strait Islander population projections are important for supporting national reporting on the health and socio-economic wellbeing of the Aboriginal and Torres Strait Islander population.

    What is the difference between a projection and forecast?

    ABS population projections do not predict or forecast how the Aboriginal and Torres Strait Islander population will look in the future. They do not incorporate any non-demographic factors which influence population change, such as changes in an individual’s decision to identify as Aboriginal and/or Torres Strait Islander, government policy, improvements in health treatment or the occurrence of natural disasters. Projections only show how the Aboriginal and Torres Strait Islander population would change if the demographic assumptions made were to eventuate over the projection period. This may or may not happen.

    What method does ABS use to produce population projections?

    ABS uses a method that involves making assumptions about future levels of Aboriginal and Torres Strait Islander fertility, paternity, mortality, net overseas migration and net interstate migration based on recent observed trends. These are applied to a starting (or base) population, split by sex and single year of age, to obtain a projected population for the following year. The assumptions are then applied to this new (projected) population to obtain a projected population for the next year, and so on through to the end of the projection period.

    What period is covered?

    The Aboriginal and Torres Strait Islander population of Australia as at 30 June 2016 is used as the base for the projection series. The Aboriginal and Torres Strait Islander population is then projected for the period 30 June 2017 to 30 June 2031 for Australia, States and Territories, Remoteness Areas and Indigenous Regions.

    What components of population change are considered in ABS population projections?

    Various population growth and demographic information is taken into account in the creation of Aboriginal and Torres Strait Islander population projections. These include:

    • Children ever born data from several Censuses
    • Total and age-specific fertility and paternity (i.e. births to Aboriginal and Torres Strait Islander fathers, where the mother’s Indigenous Status is non-Indigenous or not stated) rates
    • Ratios of males to females
    • Life expectancy at birth
    • Total and age-specific death rates;
    • Migration flows internationally and interstate.

    What assumptions are used and how are they determined?

    Assumptions are based on demographic trends observed over the past two decades in Australia. The ABS also consults various experts, government department representatives and other advisory groups at the national and state/ territory level. Three assumptions (high, medium and low) are used for fertility, paternity and mortality. Net interstate migration has one assumption based on the rates of interstate arrivals and departures observed in the 2016 Census. Net overseas migration is assumed to be zero, that is, no arrivals or departures. Observed differences between states and territories, Remoteness Areas and Indigenous Regions are also incorporated. There are nine possible combinations of assumptions at the national and state/territory levels, all of which yield different potential populations.

    What are series A, B and C?

    Future uncertainty, along with the subjective nature of assessing recent trends, means that it is useful to provide a range of possible outcomes (rather than a single series) for the future size, distribution, growth and age and sex structure of Australia's Aboriginal and Torres Strait Islander population. The ABS presents three projection series (Series A, B and C) to provide a useful and accessible range of projections for analysis and discussion.

    Further information

    For more information, please see the release Estimates and Projections, Aboriginal and Torres Strait Islander Australians, 2006 to 2032 at www.abs.gov.au. The National Information and Referral Service can also be contacted on 1300 135 070.

    Data downloads

    Table 1: Estimated resident population, Aboriginal and Torres Strait Islander Australians, Australia, states and territories by sex – 2006 to 2016

    Table 2: Estimated resident population, Aboriginal and Torres Strait Islander Australians, Australia, states and territories by sex – 2001 to 2005

    Table 3: Estimated resident population, Aboriginal and Torres Strait Islander Australians, Remoteness Areas by sex – 2006 to 2016

    Table 4: Estimated resident population, Aboriginal and Torres Strait Islander Australians, Remoteness Areas by sex – 2001 to 2005

    Table 5: Estimated resident and projected population, Aboriginal and Torres Strait Islander Australians, series B, single year of age, Australia, states and territories – 2006 to 2031

    Table 6: Estimated resident and projected population, Aboriginal and Torres Strait Islander Australians, series B, 18 years and over, Australia, states and territories by sex – 2006 to 2031

    Table 7: Projected resident population, Aboriginal and Torres Strait Islander Australians, components of change and summary statistics, Australia, states and territories – 2016 to 2031

    Table 8: Estimated resident population, Aboriginal and Torres Strait Islander Australians, single year of age, Remoteness Areas by sex – 2006 to 2016

    Table 9: Projected resident population, Aboriginal and Torres Strait Islander Australians, series B, single year of age, Remoteness Areas by sex – 2016 to 2031

    All data files

    Post release changes

    Show all

    22/07/2021 - Minor changes to projected data for 2017 to 2031 to correct a processing error. The minor changes will not materially impact calculated rates.


    12/07/2019 - Datacube 1, 'Estimates and Projections, Aboriginal and Torres Strait Islander Australians, 2006 to 2031', has been updated to include missing age group labels in the 'Persons' category that was published on 11 July 2019.

    Graph 3 in 'Assumptions' section, 'Average number of children ever born to Aboriginal and Torres Strait Islander women, Census years' has been updated to reflect correct Census years data.

    Acknowledgements

    ABS would like to thank Australian Aboriginal and Torres Strait Islander peoples for their cooperation and assistance in the collection of data, without whom this analysis would not have been possible.

    We would also like to recognise the valuable contribution made by the Aboriginal and Torres Strait Islander Demographic Statistics Expert Advisory Group, who provided technical advice and expertise on assumptions used to produce the 2006-2031 Aboriginal and Torres Strait Islander estimates and projections reported in this release.

    Previous catalogue number

    This release previously used catalogue number 3238.0.