Population

Mnemonic Variable Release 
AGE10PAge in ten year groupsJune 2022
AGE5PAge in five year groupsJune 2022
AGEPAgeJune 2022
IFAGEPImputation flag for ageJune 2022
IFSEXPImputation flag for sexJune 2022
SEXPSexJune 2022
TISPNumber of children ever born June 2022
TISRPNumber of children ever born (ranges) June 2022

Age in ten year groups (AGE10P)

Definition

This variable collects each person's age in ten-year groups. If age is not reported, it is imputed. See Imputation flag for age (IFAGEP). For infants aged less than one year, 0 years of age is recorded.

Age is also available for 0 to 115 years singly (AGEP) and in 5-year groups (AGE5P).

Scope

All persons

Categories

CodeCategory

01

0-9 years

02

10-19 years

03

20-29 years

04

30-39 years

05

40-49 years

06

50-59 years

07

60-69 years

08

70-79 years

09

80-89 years

10

90-99 years

11

100 years and over

Number of categories: 11

Question(s) from the Census form

What is the person’s date of birth and age?

What is the person’s date of birth and age?
What is Person 1's date of birth?

If date of birth is not known, please select 'Don't know date of birth' and provide Person 1's age.

More information

Day Month Year

OR

Don't know date of birth

Age

Example

Age example
What is Person 1's date of birth?

If date of birth is not known, please select 'Don't know date of birth' and provide Person 1's age.

More information

Day Month Year

OR

Don't know date of birth (selected response)

Age years

Example

Age example
What is Person 1's date of birth?

If date of birth is not known, please select 'Don't know date of birth' and provide Person 1's age.

More information

Day Month Year
18 March 1993

OR

Don't know date of birth

Age
28 years

More Information

Additional information relating to the question on: What is the person’s date of birth and age?
What is Person 1's date of birth?

If date of birth is not known, please select 'Don't know date of birth' and provide Person 1's age.

More information

It is important to note:
• Date of birth is the date that the person was born.
• Age is required only if the person's date of birth is not known. Please report age at Census night – Tuesday 10 August 2021.

If the person is less than one year old and their date of birth is not known, enter '0' in the age box.

How this variable is created

Age is calculated from date of birth when provided, otherwise stated age is used. Where both sets of information are provided, date of birth is used to derive an age in years, except in circumstances where errors in the date of birth are identified. Age data is only output in whole years.

If neither age nor date of birth is provided, age is imputed. Imputation is a statistical process for predicting values where no response was provided to a question and a response could not be derived. There are two scenarios where this occurs:

  • when no Census form is returned
  • when a respondent does not answer the age question

Where no Census form has been returned for a dwelling that is identified by a Census Field Officer as having been occupied on Census night, people are imputed into that dwelling (both numbers and key demographic characteristics such as age, sex, marital status and usual address). Most imputed ages are attributed to imputed people.

Where a respondent does not answer the age question, age is imputed using other information on the form and using an age distribution of the population. The variable Imputation flag for age (IFAGEP) is used to indicate if a person's age has been imputed for the Census.

Where respondents report an age outside the acceptable range or where there were inconsistencies between age and relationship data, age is also imputed.

History and changes

A question relating to age has been asked in every Census since 1911. Since 2006, respondents have had the option to report either date of birth or age in years.

For 2021, question wording changed from 'or' to 'and' in both the question wording and response area. The online form has been changed to primarily ask for date of birth (DOB) and the respondent is presented with a check box if DOB is not known so that they can enter the person’s age. This is to encourage the provision of more accurate data.

Data use considerations

Age data, combined with sex data, is essential to produce accurate population estimates based on the Census count.

Age is used during processing as a cross check with other variables; for example, the age of the respondent determines whether particular questions asked in the Census are applicable.

Related variables and glossary terms

Age in five year groups (AGE5P)

Definition

This variable collects each person's age in five-year groups. If age is not reported, it is imputed. See Imputation flag for age (IFAGEP). For infants aged less than one year, 0 years of age is recorded.

Age is also available for 0 to 115 years singly (AGEP) and 10-year groups (AGE10P).

Scope

All persons

Categories

CodeCategory

01

0-4 years

02

5-9 years

03

10-14 years

04

15-19 years

05

20-24 years

06

25-29 years

07

30-34 years

08

35-39 years

09

40-44 years

10

45-49 years

11

50-54 years

12

55-59 years

13

60-64 years

14

65-69 years

15

70-74 years

16

75-79 years

17

80-84 years

18

85-89 years

19

90-94 years

20

95-99 years

21

100 years and over

Number of categories: 21

Question(s) from the Census form

What is the person’s date of birth and age?

What is the person’s date of birth and age?
What is Person 1's date of birth?

If date of birth is not known, please select 'Don't know date of birth' and provide Person 1's age.

More information

Day Month Year

OR

Don't know date of birth

Age

Example

Age example
What is Person 1's date of birth?

If date of birth is not known, please select 'Don't know date of birth' and provide Person 1's age.

More information

Day Month Year

OR

Don't know date of birth (selected response)

Age years

Example

Age example
What is Person 1's date of birth?

If date of birth is not known, please select 'Don't know date of birth' and provide Person 1's age.

More information

Day Month Year
18 March 1993

OR

Don't know date of birth

Age
28 years

More information

Additional information relating to the question on: What is the person’s date of birth and age?
What is Person 1's date of birth?

If date of birth is not known, please select 'Don't know date of birth' and provide Person 1's age.

More information

It is important to note:
• Date of birth is the date that the person was born.
• Age is required only if the person's date of birth is not known. Please report age at Census night – Tuesday 10 August 2021.

If the person is less than one year old and their date of birth is not known, enter '0' in the age box.

How this variable is created

Age is calculated from date of birth when provided, otherwise stated age is used. Where both sets of information are provided, date of birth is used to derive an age in years, except in circumstances where errors in the date of birth are identified. Age data is only output in whole years.

If neither age nor date of birth is provided, age is imputed. Imputation is a statistical process for predicting values where no response was provided to a question and a response could not be derived. There are two scenarios where this occurs:

  • when no Census form is returned
  • when a respondent does not answer the age question

Where no Census form has been returned for a dwelling that is identified by a Census Field Officer as having been occupied on Census night, people are imputed into that dwelling (both numbers and key demographic characteristics such as age, sex, marital status and usual address). Most imputed ages are attributed to imputed people.

Where a respondent does not answer the age question, age is imputed using other information on the form and using an age distribution of the population. The variable Imputation flag for age (IFAGEP) is used to indicate if a person's age has been imputed for the Census.

Where respondents report an age outside the acceptable range or where there were inconsistencies between age and relationship data, age is also imputed.

History and changes

A question relating to age has been asked in every Census since 1911. Since 2006, respondents have had the option to report either date of birth or age in years.

For 2021, question wording changed from 'or' to 'and' in both the question wording and response area. The online form has been changed to primarily ask for date of birth (DOB) and the respondent is presented with a check box if DOB is not known so that they can enter the person’s age. This is to encourage the provision of more accurate data.

Data use considerations

Age data, combined with sex data, is essential to produce accurate population estimates based on the Census count.

Age is used during processing as a cross check with other variables; for example, the age of the respondent determines whether particular questions asked in the Census are applicable.

Related variables and glossary terms

Age (AGEP)

Definition

This variable collects each person's age. If age is not reported, it is imputed. See Imputation flag for age (IFAGEP). For infants aged less than one year, 0 years of age is recorded.

Data is also available in 5 year groups (AGE5P) and 10 year groups (AGE10P).

Scope

All persons

Categories

CodeCategory

000-115

0 to 115 years of age singly

Number of categories: 116

Question(s) from the Census form

What is the person’s date of birth and age?

What is the person’s date of birth and age?
What is Person 1's date of birth?

If date of birth is not known, please select 'Don't know date of birth' and provide Person 1's age.

More information

Day Month Year

OR

Don't know date of birth

Age
Age example
What is Person 1's date of birth?

If date of birth is not known, please select 'Don't know date of birth' and provide Person 1's age.

More information

Day Month Year

OR

Don't know date of birth (selected response)

Age years

Example

Age example
What is Person 1's date of birth?

If date of birth is not known, please select 'Don't know date of birth' and provide Person 1's age.

More information

Day Month Year
18 March 1993

OR

Don't know date of birth

Age
28 years

More Information

Additional information relating to the question on: What is the person’s date of birth and age?
What is Person 1's date of birth?

If date of birth is not known, please select 'Don't know date of birth' and provide Person 1's age.

More information

It is important to note:
• Date of birth is the date that the person was born.
• Age is required only if the person's date of birth is not known. Please report age at Census night – Tuesday 10 August 2021.

If the person is less than one year old and their date of birth is not known, enter '0' in the age box.

How this variable is created

Age is calculated from date of birth when provided, otherwise stated age is used. Where both sets of information are provided, date of birth is used to derive an age in years, except in circumstances where errors in the date of birth are identified. Age data is only output in whole years.

If neither age nor date of birth is provided, age is imputed. Imputation is a statistical process for predicting values where no response was provided to a question and a response could not be derived. There are two scenarios where this occurs:

  • when no Census form is returned
  • when a respondent does not answer the age question

Where no Census form has been returned for a dwelling that is identified by a Census Field Officer as having been occupied on Census night, people are imputed into that dwelling (both numbers and key demographic characteristics such as age, sex, marital status and usual address). Most imputed ages are attributed to imputed people.

Where a respondent does not answer the age question, age is imputed using other information on the form and using an age distribution of the population. The variable Imputation flag for age (IFAGEP) is used to indicate if a person's age has been imputed for the Census.

Where respondents report an age outside the acceptable range or where there were inconsistencies between age and relationship data, age is also imputed.

History and changes

A question relating to age has been asked in every Census since 1911. Since 2006, respondents have had the option to report either date of birth or age in years.

For 2021, question wording changed from 'or' to 'and' in both the question wording and response area. The online form has been changed to primarily ask for date of birth (DOB) and the respondent is presented with a check box if DOB is not known so that they can enter the person’s age. This is to encourage the provision of more accurate data.

Data use considerations

Age data, combined with sex data, is essential to produce accurate population estimates based on the Census count.

Age is used during processing as a cross check with other variables; for example, the age of the respondent determines whether particular questions asked in the Census are applicable.

Related variables and glossary terms

Imputation flag for age (IFAGEP)

Definition

This variable indicates if a person's age was imputed. Imputation is a statistical process for predicting values where no response was provided to a question and a response could not be derived.

See also Age (AGEP).

Scope

All persons

Categories

CodeCategory

01

Age not imputed

02

Age imputed

Number of categories: 2

Question(s) from the Census form

What is the person’s date of birth and age?

What is the person’s date of birth and age?
What is Person 1's date of birth?

If date of birth is not known, please select 'Don't know date of birth' and provide Person 1's age.

More information

Day Month Year

OR

Don't know date of birth

Age

Example

Age example
What is Person 1's date of birth?

If date of birth is not known, please select 'Don't know date of birth' and provide Person 1's age.

More information

Day Month Year

OR

Don't know date of birth (selected response)

Age years

Example

Age example
What is Person 1's date of birth?

If date of birth is not known, please select 'Don't know date of birth' and provide Person 1's age.

More information

Day Month Year
18 March 1993

OR

Don't know date of birth

Age
28 years

More information

Additional information relating to the question on: What is the person’s date of birth and age?
What is Person 1's date of birth?

If date of birth is not known, please select 'Don't know date of birth' and provide Person 1's age.

More information

It is important to note:
•Date of birth is the date that the person was born.
•Age is required only if the person's date of birth is not known. Please report age at Census night – Tuesday 10 August 2021.

If the person is less than one year old and their date of birth is not known, enter '0' in the age box.

How this variable is created

When age is imputed this variable is coded to ‘02 Age imputed’. See Age (AGEP) for methods on how age is imputed.

History and changes

No changes have been made for 2021.

Data use considerations

Imputation flag for age (IFAGEP) can be used to identify how many respondents’ age was imputed at different geographical levels.

Related variables and glossary terms

Imputation flag for sex (IFSEXP)

Definition

This variable indicates if a person's binary sex was imputed. Imputation is a statistical process for predicting values where no response was provided to a question and a response could not be derived.

Scope

All persons

Categories

CodeCategory

01

Sex not imputed

02

Sex imputed

Number of categories:  2

Question(s) from the Census form

Is the person: Male; Female; Non-binary sex

Is the person: Male; Female
Is Person 1:

If these options do not describe the person, they can Select something other than male or female.

Male

Female

Question presented when 'Select something other than male or female' hyperlink is chosen

Is the person: Male; Female; Non-binary sex
Is Person 1:

If the person does not wish to select ‘Non-binary sex’, they can Select only male or female.

A person may choose to select more than one response (for example, male and non-binary sex, or female and non-binary sex).

If ‘Non-binary sex’ is selected, there will be an opportunity to provide more information.

Male

Female

Non-binary sex

Example

Imputation flag for sex example - Female, Non-binary sex response selected
Is Person 1:

If the person does not wish to select ‘Non-binary sex’, they can Select only male or female.

A person may choose to select more than one response (for example, male and non-binary sex, or female and non-binary sex).

If ‘Non-binary sex’ is selected, there will be an opportunity to provide more information.

Male

Female (selected response)

Non-binary sex (selected response)
Please specify (optional)

How this variable is created

This variable is created during the processing of the Sex (SEXP) variable. When a record has sex imputed it is coded to ‘02 Sex imputed’ and where a record uses information from the Census form it is coded to ’01 Sex not imputed’.

See the Sex (SEXP) variable for details on the imputation process in the ‘How this variable is created’ section.

History and changes

The Imputation flag for sex (IFSEXP) variable was first used in 2016.

Related variables and glossary terms

Sex (SEXP)

Definition

This variable records each person’s sex. A person's sex is based on their sex characteristics, such as their chromosomes, hormones and reproductive organs. If sex is not stated it is imputed.

See also Imputation flag for sex (IFSEXP).

Scope

All persons

Categories

CodeCategory

1

Male

2

Female

Number of categories:  2

Question(s) from the Census form

Is the person: Male; Female; Non-binary sex

Is the person: Male; Female
Is Person 1:

If these options do not describe the person, they can Select something other than male or female.

Male

Female

Question presented when 'Select something other than male or female' hyperlink is chosen

Is the person: Male; Female; Non-binary sex
Is Person 1:

If the person does not wish to select ‘Non-binary sex’, they can Select only male or female.

A person may choose to select more than one response (for example, male and non-binary sex, or female and non-binary sex).

If ‘Non-binary sex’ is selected, there will be an opportunity to provide more information.

Male

Female

Non-binary sex

Example

Sex example - Female, Non-binary sex response selected
Is Person 1:
If the person does not wish to select ‘Non-binary sex’, they can Select only male or female.

A person may choose to select more than one response (for example, male and non-binary sex, or female and non-binary sex).

If ‘Non-binary sex’ is selected, there will be an opportunity to provide more information.

Male

Female (selected response)

Non-binary sex (selected response)
Please specify (optional)

How this variable is created

Responses to the sex question are captured from mark box responses on the form so the risk of processing error is minimal. Male, female, and non-binary sex are the three options. A person can select one response only or they can select more than one response (male and non-binary sex, or female and non-binary sex). The online Census form allows respondents who select the non-binary sex response to provide further information. This field is optional and can be used to describe the circumstances specific to the person responding.

Note that data collected from the sex question will be reported in most Census data releases as ‘Male’ or ‘Female’ in order to maintain the quality of standard products at the small area level. Where a respondent has provided a male or female response and a non-binary sex response, the male or female response will be used to determine the binary sex variable. Otherwise, sex will be derived by a statistical process using random allocation.

Binary sex is also imputed when the question is not answered. If sex is missing on partially completed forms, it is imputed by automated and then manual coding processes, if required, using relevant information provided on the incomplete form. For records that could not be resolved through this process, sex is derived by a statistical process using random allocation.

For private dwellings where a form is not returned and the number of males and females is unknown, two imputation processes are performed. Initially, these records have their number of males and females imputed using hotdecking. Then a second imputation (also using hotdecking) is run to impute the key demographic variables (age, marital status and usual address) for the newly created person records.

If a person in a non-private dwelling did not return a form, their demographic characteristics are copied from another person in a similar non-private dwelling using Type of non-private dwelling (NPDD).

History and changes

A question on Sex has been asked at every Census since 1911.

In 2016, respondents had the option to respond as 'other sex'. If a person wanted to identify as other than male or female, they were instructed to call the Census Inquiry Service for information on how to identify on the Census forms. To respond online, they were given specific login details to access an alternate form which allowed them to select 'other' and could enter in information in a 'please specify' text. To respond on paper form, they were instructed to write on the right-hand side of the response area and these were checked manually to record a respondent's 'other sex' category. 

In 2021, ‘Non-binary sex’ option was added as an input category to the standard question. However, the output categories for this variable are unchanged for 2021.

Data use considerations

The question on the Census asks about a person’s sex, which is based on their sex characteristics, such as their chromosomes, hormones, and reproductive organs.

Respondents were instructed to answer in the way that applies to them, with the guidance that the non-binary sex category was included to provide options for people who are not exclusively male or female, for example people with variations in sex characteristics or intersex.

Feedback from respondents and members of the LGBTIQ+ community during Census enumeration identified some confusion on how to answer the question for people who are gender diverse, gender non-binary or transgender. It is likely therefore that some respondents answered based on their gender identity rather than their biological sex. Research undertaken by the ABS in developing the sex question for the Census, suggests that this was also the case in previous Censuses. This is not able to be quantified for respondents who selected a binary sex response, for example a person born male but living as a woman for many years may select ‘female’ as their response, noting this may be balanced out with respondents who were born female but living as a man and selecting ‘male’ as their response.

The ABS will release data on the number and characteristics of people who responded with ‘Non-binary sex’ in an analytical article published in late 2022. Analysis of the responses to the further information text will also be presented in a separate article published at the same time.

Related variables and glossary terms

Number of children ever born (TISP)

Definition

This variable records the number of children ever born to each female aged 15 years and over.

Scope

Females aged 15 years and over

Categories

CodeCategory

00

No children

01

1 child

02

2 children

03

3 children

04

4 children

05

5 children

06

6 children

07

7 children

08

8 children

09

9 children

10

10 children

11

11 children

12

12 children

13

13 children

14

14 children

15

15 children

16

16 children

17

17 children

18

18 children

19

19 children

20

20 children

21

21 children

22

22 children

23

23 children

24

24 children

25

25 children

26

26 children

27

27 children

28

28 children

29

29 children

30

30 or more children

&&

Not stated

@@

Not applicable

VV

Overseas visitor

Number of categories:  34

Not applicable (@@) category comprises:

  • Males
  • Females aged under 15 years

Question(s) from the Census form

For each female, how many babies has she ever given birth to?

For each female, how many babies has she ever given birth to?
How many babies has Person 1 ever given birth to?

Exclude adopted, foster and step children.

More information

Number of babies

More information

Additional information relating to the question on: For each female, how many babies has she ever given birth to?
How many babies has Person 1 ever given birth to?

Exclude adopted, foster and step children.

More information

Enter the number of children the person has given birth to. This question is only applicable to females aged 15 years or over.

Information obtained from this question is used to calculate measures of lifetime fertility. This information will assist with calculating future population projections for Australia and provide information about the impact of fertility trends on social issues, such as the ageing of the population.

How this variable is created

Data for this variable is captured automatically from written numeric responses, or the 'None' response category on the paper form. All numeric responses are accepted as reported.

History and changes

This question was first asked in the 1981 Census.

For 2016, an instruction on the form to include live births only was removed, due to evidence of the sensitivities of this question which cannot be overcome effectively in a self-report questionnaire. This instruction was previously included to collect births information according the United Nations Standard.

No changes have been made for 2021.

Data use considerations

The data may include a small proportion of persons with unusually high numbers of children ever born, as all numeric responses are accepted as reported.

For the Census online form, females aged 15 years and over were asked this question. Male respondents and people who responded only with non-binary sex were not asked this question.

Related variables and glossary terms

Number of children ever born (ranges) (TISRP)

Definition

This variable records the number of children ever born to each female aged 15 years and over in ranges.

Scope

Females aged 15 years and over

Categories

CodeCategory

0

No children

1

One child

2

Two children

3

Three children

4

Four children

5

Five children

6

Six children

7

Seven children

8

Eight or more children

&

Not stated

@

Not applicable

V

Overseas visitor

Number of categories:  12

Not applicable (@@) category comprises:

  • Males
  • Females aged under 15 years

Question(s) from the Census form

For each female, how many babies has she ever given birth to?

For each female, how many babies has she ever given birth to?
How many babies has Person 1 ever given birth to?

Exclude adopted, foster and step children.

More information

Number of babies

More Information

Additional information relating to the question on: For each female, how many babies has she ever given birth to?
How many babies has Person 1 ever given birth to?

Exclude adopted, foster and step children.

More information

Enter the number of children the person has given birth to. This question is only applicable to females aged 15 years or over.

Information obtained from this question is used to calculate measures of lifetime fertility. This information will assist with calculating future population projections for Australia and provide information about the impact of fertility trends on social issues, such as the ageing of the population.

How this variable is created

Data for this variable is captured automatically from written numeric responses, or the 'None' response category on the paper form. All numeric responses are accepted as reported.

History and changes

This question was first asked in the 1981 Census.

For 2016, an instruction on the form to include live births only was removed, due to evidence of the sensitivities of this question which cannot be overcome effectively in a self-report questionnaire. This instruction was previously included to collect births information according the United Nations Standard.

No changes have been made for 2021.

Data use considerations

The data may include a small proportion of persons with unusually high numbers of children ever born, as all numeric responses are accepted as reported.

For the Census online form, females aged 15 years and over were asked this question. Male respondents and people who responded only with non-binary sex were not asked this question.

Related variables and glossary terms