Twenty years of population change
The median age (the age at which half the population is older and half is younger) of the Australian population has increased by 2 years over the last two decades, from 35 years at 30 June 1999 to 37 years at 30 June 2019. Between 30 June 2018 and 30 June 2019 the median age remained steady at 37 years.
Tasmania experienced the largest increase in median age over the last 20 years, increasing by 6 years from 36 years in 1999 to 42 years in 2019. Interstate migration of younger adults from Tasmania to the Australian mainland has contributed to this accelerated ageing. For further information, see Migration, Australia (cat. no. 3412.0).
At 30 June 2019, Tasmania had the highest median age of all the states and territories (42 years), followed by South Australia (40 years). The Northern Territory had the lowest median age (33 years), followed by the Australian Capital Territory (35 years).
Median age of population (a) - at 30 June
(a) The age at which half the population is older and half younger.
Like most developed countries, Australia's population is ageing as a result of sustained low fertility and increasing life expectancy. This has resulted in proportionally fewer children (under 15 years of age) in the population and a larger proportion of people aged 65 and over.
Population change, Age groups - 1999 to 2019
CHILDREN (AGED 0–14 YEARS)
In the 20 years between 1999 and 2019, the proportion of children decreased from 20.9% to 18.7% of the total population.
In the year ending 30 June 2019, the number of children increased by 1.0% (48,900 people) compared with an increase of 1.2% (53,600 people) in the previous year. Over this period, the number of 0-4 year olds decreased by 5,100 (0.3%), 5-9 year olds increased by 14,200 (0.9%), and those aged between 10-14 years increased by 39,800 (2.6%).
In the year ending 30 June 2019, the Australian Capital Territory had the largest percentage increase in the number of children (1.9%), followed by Victoria (1.3%), Queensland (1.1%) and New South Wales (1.0%). The Northern Territory was the only state or territory with a percentage decrease (1.0%).
WORKING-AGE POPULATION (AGED 15–64 YEARS)
At 30 June 1999, two out of three people were aged between 15 and 64 years – usually referred to as the 'working-age population'. This proportion increased to a high of 67.5% in 2009, before declining to 65.4% by 30 June 2019.
Over the 20 years to 30 June 2019, the working-age population grew by 32.0%, slower than the growth of the remaining population (40.4%) The slower growth in the working-ages has occurred since 2010.
Over the five years to 30 June 2019, the working-age population grew by 6.4%, compared to 11.4% for the remainder. The main contributor to the increased growth of the non-working-ages was the growth in the population aged 65 and over.
In the year ending 30 June 2019, the Australian working-age population increased by 1.3% (or 207,400 persons). During this period, the working-age population in Victoria grew by 2.0%, higher than the national growth rate. In contrast, the population of 15-64 year olds declined in the Northern Territory by 0.9%.
There were 290,600 young people aged 15 years who entered the working-age population while 254,800 people turned 65 years and left the working-age population in the year ended 30 June 2019.
Working-age & non-working-age population annual growth rate comparison, Australia
PEOPLE AGED 65 YEARS AND OVER
Over the 20 years between 1999 and 2019, the proportion of the population aged 65 years and over increased from 12.3% to 15.9%. This group is projected to increase more rapidly over the next decade, as further cohorts of baby boomers (those born between the years 1946 and 1964) turn 65. By the end of the 2019 calendar year, nine of these birth-year cohorts will have reached age 65 and there are ten remaining.
Proportion of population aged 65 years & over
In the year ending 30 June 2019, the number of people aged 65 years and over increased by 125,400 people (or 3.2%).
In the year ending 30 June 2019, the population aged 65 years and over grew in all states and territories. The largest percentage increase in this group was in the Northern Territory (4.9%), followed by Western Australia and Queensland (3.9%).
PEOPLE AGED 85 YEARS AND OVER
Over the past two decades, the number of people aged 85 years and over increased by 117.1%, compared with a total population growth of 34.8% over the same period.
In the year ending 30 June 2019, the number of people aged 85 years and over increased by 12,600 people (2.5%) to reach 515,700. There were more females (317,600) than males (198,100) in this age group, which reflects the higher life expectancy for females.
Over the same period, the largest percentage increases of people aged 85 years and over occurred in the Northern Territory (6.2%), followed by Western Australia (3.3%), Queensland and Tasmania (3.1%) Victoria and the Australian Capital Territory (2.9%), New South Wales (2.0%), and South Australia (1.2%).
The sex ratio at birth is approximately 106 males per 100 females. Higher male mortality rates at younger ages result in the ratio approaching 100 by the age of 30. Overseas migration can influence the sex ratio, especially in the working ages where there has historically been a greater proportion of male migrants. Above age 75, the sex ratio reduces markedly due to the impact of higher male mortality in this population group.
Sex ratio (a), Age groups - at 30 June 2019
(a) Number of males per 100 females
At 30 June 2019, the sex ratio of the total population of Australia was 98.4 males per 100 females. At age 0, the sex ratio for Australia at 30 June 2018 was 106.0 males per 100 females. The larger amount of males at younger ages contrasts with the opposite situation in the older ages, which is attributed to female longevity.
At 30 June 2019, the Northern Territory had the highest sex ratio out of the states and territories at 106.9, followed by Western Australia (99.8), New South Wales (98.6), Victoria (98.1),Tasmania (98.0), Queensland and the Australian Capital Territory (97.8). South Australia had the lowest ratio at 97.7.
Sex ratio (a), States and territories - at 30 June 2019
(a) Number of males per 100 females