GLOSSARY

12/16 month rule

A method for measuring an overseas traveller's duration of stay or absence which takes an approach to measure usual residence that does not have to be continuous, as opposed to the continuous approach used under a '12/12 month rule'. Under a '12/16 month rule', incoming overseas travellers (who are not currently counted in the population) must be resident in Australia for a total period of 12 months or more, during the 16 month follow-up period to then be included in the estimated resident population. Similarly, those travellers departing Australia (who are currently counted in the population) must be absent from Australia for a total of 12 months or more during the 16 month follow-up period to then be subtracted from the estimated resident population.

The 12/16 month rule therefore takes account of those persons who may have left Australia briefly and returned, while still being resident for 12 months out of 16. Similarly, it takes account of Australians who live most of the time overseas but periodically return to Australia for short periods.

Age-specific fertility rates

Age-specific fertility rates (ASFR) are the number of live births (occurred or registered) during the calendar year, according to the age of the mother, per 1,000 of the female estimated resident population of the same age at 30 June. For calculating these rates, births to mothers under 15 years are included in the 15-19 years age group, and births to mothers aged 50 years and over are included in the 45-49 years age group. Pro rata adjustment is made for births for which the age of the mother is not given.

Aboriginal and Torres Strait Islander birth

The birth of a live-born child where at least one parent reported themselves as being an Aboriginal person, Torres Strait Islander, or both on the birth registration form.

Average annual growth rate

The average annual growth rate, r, is calculated as a percentage using the formula:



where P₀ is the population at the start of the period, P_n is the population at the end of the period and n is the length of the period between P₀ and P_n in years.

Baby boom

Baby boom refers to the generation born between the end of World War II and the mid-1960s. Baby boomers are usually taken to be those born in the years 1946 to 1965 inclusive.

Balance of state or territory

The aggregation of all Statistical Divisions (SDs) within a state or territory other than its Capital City SD. See Major Statistical Region in Australian Standard Geographical Classification (ASGC) (cat. no. 1216.0).

Birth

The delivery of a child, irrespective of the duration of pregnancy, who, after being born, breathes or shows any evidence of life such as a heartbeat.

Childbearing ages

See Reproductive lifetime.

Collection District (CD)

Until the 2006 Census, the smallest geographical area for which the census data were available. From 2011, CDs have been replaced with Statistical Areas Level 1.

Completed fertility

Completed fertility represents the average number of births a cohort of females have borne over their reproductive lifetimes.

Confinement

A pregnancy which results in at least one live birth.

Crude birth rate

The crude birth rate is the number of live births registered during the calendar year per 1,000 estimated resident population at 30 June of that year. For years prior to 1992, the crude birth rate was based on the mean estimated resident population for the calendar year.

Estimated resident population (ERP)

The official measure of the population of Australia is based on the concept of residence. It refers to all people, regardless of nationality or citizenship, who usually live in Australia, with the exception of foreign diplomatic personnel and their families. It includes usual residents who are overseas for less than 12 months. It excludes overseas visitors who are in Australia for less than 12 months.

Ex-nuptial birth

An ex-nuptial birth is the birth of a child whose parents are not legally married to each other at the time of the child's birth.

Intercensal discrepancy

Intercensal discrepancy is the difference between two estimates at 30 June of a Census year population, the first based on the latest Census and the second arrived at by updating the 30 June estimate of the previous Census year with intercensal components of population change which take account of information available from the latest Census. It is caused by errors in the start and/or finish population estimates and/or in estimates of births, deaths or migration in the intervening period which cannot be attributed to a particular source. For further information, see Population Estimates: Concepts, Sources and Methods, 2009 (cat. no. 3228.0.55.001).

Live birth

See Birth.

Local Government Area (LGA)

An ABS approximation of an officially gazetted LGA as defined by each state and territory local government department. LGAs cover incorporated areas of Australia, which are legally designated areas for which incorporated local governing bodies have responsibility. The major areas of Australia not administered by incorporated bodies are the northern parts of South Australia and all of the Australian Capital Territory and the Other Territories. These regions are identified as 'Unincorporated' in the ABS LGA structure.

For more information, please refer to Australian Statistical Geography Standard (ASGS): Volume 3 - Non ABS Structures, July, 2012 (cat. no. 1270.0.55.003).

Marital status

Two separate concepts of marital status are measured by the Australian Bureau of Statistics. These are registered marital status and social marital status.

Registered marital status refers to formally registered marriages and divorces. Registered marital status is a person's relationship status in terms of whether he or she has, or has had, a registered marriage with another person. Accordingly, people are classified as either 'never married', 'married', widowed' or 'divorced'. Statistics included in this publication are based on registered marital status.

Social marital status is the relationship status of an individual with reference to another person who is usually resident in the household. A marriage exists when two people live together as husband and wife, or partners, regardless of whether the marriage is formalised through registration. Individuals are, therefore, regarded as married if they are in a de facto marriage, or if they are living with the person to whom they are registered as married. Under social marital status, a person is classified as either 'married' or 'not married' with further disaggregation of 'married' to distinguish 'registered married' from 'de facto married'.

Median age of mother at confinement

The median age of mother at confinement measures the median age of females who gave birth in a particular year. This publication reports on median age of mother at confinement.

Median value

For any distribution the median value (age, duration, interval) is that value which divides the relevant population into two equal parts, half falling below the value, and half exceeding it. Where the value for a particular record has not been stated, that record is excluded from the calculation.

Mortality

Death.

Multiple birth

A multiple birth is a confinement which results in two or more children, at least one of which is live-born.

Natural increase

Excess of births over deaths.

Net overseas migration (NOM)

Net overseas migration is the net gain or loss of population through immigration to Australia and emigration from Australia. It is:

• based on an international traveller's duration of stay being in or out of Australia for 12 months or more; and
• the difference between:
  • the number of incoming international travellers who stay in Australia for 12 months or more, who are not currently counted within the population, and are then added to the population (NOM arrivals); and
  • the number of outgoing international travellers (Australian residents and long-term visitors to Australia) who leave Australia for 12 months or more, who are currently counted within the population, and are then subtracted from the population (NOM departures).

Under the current method for estimating final net overseas migration, this term is based on a traveller's actual duration of stay or absence using the '12/16 month rule'. Preliminary NOM estimates are modelled on patterns of traveller behaviours observed in final NOM estimates for the same period one year earlier.

Net reproduction rate

The net reproduction rate represents the average number of daughters that would be born to a group of females if they are subject to the fertility and mortality rates of a given year during their future life. It indicates the extent to which the population would reproduce itself. The net reproduction rate is obtained by multiplying the age-specific birth rates (for female births only) by the proportion of survivors at corresponding ages in a life table and adding the products.

Nuptial birth

A nuptial birth is the birth of a child born of parents who are legally married at the time of the child's birth.

Nuptiality

Nuptiality relates to the registered marital status of persons and the events such as marriages, divorces and widowhood. Confinements and births are identified as being nuptial where the father registered was married to the mother at the time of birth, or where the husband died during pregnancy. Confinements and children of Indigenous mothers considered to be tribally married are classified as nuptial. Other confinements, and the children resulting from them, are classified as ex-nuptial whether or not both parents were living together at the time of birth.

Other Territories

Following the 1992 amendments to the Acts Interpretation Act to include the Indian Ocean Territories of Christmas Island and the Cocos (Keeling) Islands as part of geographic Australia, another category at the state and territory level has been created, known as Other Territories. Other Territories include Jervis Bay Territory, previously included with the Australian Capital Territory, as well as Christmas Island and the Cocos (Keeling) Islands.

Parity

Parity refers to the number of live births a woman has had previous to the most recent birth. Parity is also an attribute of any live birth, being the order of that birth (e.g. first birth, second birth, and so on) of a woman.

Paternity acknowledged birth

A paternity acknowledged birth refers to an ex-nuptial birth where paternity was acknowledged (on the birth registration form).

Paternity not acknowledged birth

A paternity not acknowledged birth refers to an ex-nuptial birth where paternity was not acknowledged (on the birth registration form).

Population growth

For Australia, population growth is the sum of natural increase and net overseas migration. For states and territories, population growth also includes net interstate migration. After the Census, intercensal population growth also includes an allowance for intercensal discrepancy.

Previous births

Previous births refer to children born alive (who may or may not be living) to a mother prior to the registration of the current birth in the processing period. In some states, legitimised and legally adopted children may also be included.

Due to variation in data collection and processing methods across states and territories, different definitions of the concept of previous births have been applied.

Changes in ABS processing of data collected by state/territory Registrars of Births, Deaths and Marriages for 2007 have resulted in the availability of improved information on previous births to mothers. Prior to 2007, ABS published information on previous births of the mother from the current relationship only, for all states and territories. From 2007, data on previous births for all relationships (both current and previous, if any) of the mother are collected for all states and territories, excluding Victoria and Queensland.

Previous children

See Previous births.

Rate of population growth

Population change over a period as a proportion (percentage) of the population at the beginning of the period.

Remoteness Area (RA)

Within the Australian Standard Geographical Classification (ASGC), the Remoteness Structure classification comprises six categories called Remoteness Areas (RAs). Each RA is created from the grouping of Collection Districts (CDs) identifying a (non-contiguous) region in Australia having a particular degree of remoteness.

Remoteness categories will continue as part of the Australian Statistical Geography Standard (ASGS). Within the ASGS, the remoteness classification will comprise six categories or Remoteness Areas (RAs), being a grouping of Statistical Areas Level 1 (SA1s) instead of CDs.

The RA categories for Australia disseminated in this publication are: Major Cities, Inner Regional, Outer Regional, Remote, and Very Remote. The sixth category is Migratory and is not available for dissemination.

Replacement fertility

Replacement level fertility is the number of babies a female would need to have over her reproductive life span to replace herself and her partner. Given the current mortality of females up to age 49 years, replacement fertility is estimated at around 2.1 babies per female.

Reproductive lifetime

Women's childbearing years, usually assumed as the ages from 15 to 49 years for the purpose of analysis. In this publication, births to women less than 15 years are included in the 15 years age group and those 50 years and older are included in the 49 years age group.

Sex ratio

The sex ratio relates to the number of males per 100 females.

State or territory of registration

State or territory of registration refers to the state or territory in which the event was registered.

State or territory of usual residence

State or territory of usual residence refers to the state or territory of usual residence of:

• the population (estimated resident population);
• the mother (birth collection); and
• the deceased (death collection).

Statistical Area Level 1 (SA1)

An area defined in the Australian Statistical Geography Standard and designed as the smallest unit for the release of Census data. They generally have a population of 200 to 800 people, and an average population of about 400 people. SA1s in remote and regional areas generally have smaller populations than those in urban areas. There are approximately 55,000 SA1s and they cover the whole of Australia without gaps or overlaps. Births data are not available at this level of geography.

For more information, please refer to Australian Statistical Geography Standard (ASGS): Volume 1 - Main Structure and Greater Capital City Statistical Areas (cat. no. 1270.0.55.001).

Statistical Area Level 2 (SA2)

A general-purpose medium-sized area defined in the Australian Statistical Geography Standard and built from whole SA1s. They aim to represent communities that interact together socially and economically. SA2s are based on officially gazetted suburbs and localities. In urban areas SA2s largely conform to one or more whole suburbs, while in rural areas they generally define the functional zone of a regional centre. SA2s generally have a population range of 3,000 to 25,000 people, and an average population of about 10,000 people. There are approximately 2,200 SA2s and they cover the whole of Australia without gaps or overlaps. SA2s are the base unit for preparing sub-state fertility statistics.

For more information, please refer to Australian Statistical Geography Standard (ASGS): Volume 1 - Main Structure and Greater Capital City Statistical Areas (cat. no. 1270.0.55.001).

Statistical Area Level 3 (SA3)

An area defined in the Australian Statistical Geography Standard and built up from SA2s which provides a standardised regional breakup of Australia. SA3s aim to create a standard framework for the analysis of ABS data at the regional level through clustering groups of whole SA2s that have similar regional characteristics. Their boundaries reflect a combination of widely recognised informal regions as well as existing administrative regions such as State Government Regions in rural areas and Local Government Areas in urban areas. SA3s generally range in population from 30,000 to 130,000 people. There are around 330 SA2s and they cover the whole of Australia without gaps or overlaps.

For more information, please refer to Australian Statistical Geography Standard (ASGS): Volume 1 - Main Structure and Greater Capital City Statistical Areas (cat. no. 1270.0.55.001).

Statistical Area Level 4 (SA4)

An area defined in the Australian Statistical Geography Standard and designed for the output of labour force data and to reflect labour markets. In rural areas SA4s generally represent aggregations of multiple small labour markets with socioeconomic connections or similar industry characteristics. Large regional city labour markets are generally defined by a single SA4. Within major metropolitan labour markets SA4s represent sub-labour markets. SA4s are built from whole SA3s. They generally have a population over 100,000 people to enable accurate labour force survey data to be generated. There are 88 SA4s and they cover the whole of Australia without gaps or overlaps.

For more information, please refer to Australian Statistical Geography Standard (ASGS): Volume 1 - Main Structure and Greater Capital City Statistical Areas (cat. no. 1270.0.55.001).

Statistical Division (SD)

An area defined in the Australian Standard Geographical Classification which represents a large, general purpose, regional type geographic area. SDs represent relatively homogeneous regions characterised by identifiable social and economic links between the residents and between the economic units within the region, under the unifying influence of one or more major towns or cities. They consist of one or more Statistical Subdivisions and cover the whole of Australia without gaps or overlaps.

For more information, please refer to Australian Standard Geographical Classification (ASGC) (cat. no. 1216.0).

Statistical Local Area (SLA)

An area defined in the Australian Standard Geographical Classification that is a Local Government Areas, or part thereof. Where there is no incorporated body of local government, SLAs are defined to cover the unincorporated areas. In Census years, up until the 2006 Census, SLAs consisted of one or more whole Collection Districts. SLAs cover the whole of Australia without gaps or overlaps.

For more information, please refer to Australian Standard Geographical Classification (ASGC) (cat. no. 1216.0).

Statistical Subdivision (SSD)

An area defined in the Australian Standard Geographical Classification which represents an intermediate level, general purpose, regional type geographic unit. SSDs consist of one or more Statistical Local Areas and cover the whole of Australia without gaps or overlaps.

For more information, please refer to Australian Standard Geographical Classification (ASGC) (cat. no. 1216.0).

Teenage fertility rate

The number of births during the calendar year to women aged 15-19 years, per 1,000 female estimated resident population aged 15-19 years at 30 June of the same year. Births to women aged under 15 years are included.

Total fertility rate

The sum of age-specific fertility rates (live births at each age of mother per 1,000 of the female population of that age) divided by 1,000. It represents the number of children a female would bear during her lifetime if she experienced current age-specific fertility rates at each age of her reproductive life.

Usual residence

Usual residence within Australia refers to that address at which the person has lived or intends to live for a total of six months or more in a given reference year.

Year of occurrence

Data presented on year of occurrence basis relate to the date the birth occurred.

Year of registration

Data presented on year of registration basis relate to the date the birth was registered.