In short:
Australia's population in 2021 was almost seven times larger than in 1901.
Life expectancy from birth has increased by 26 years since the early 1900s, while fertility rates in Australia have decreased from 3.1 births per woman in 1921 to 1.7 in 2021.
About nine in 10 of Australia's population live in urban areas, compared with about 58 per cent in 1911.
Australia has changed significantly over 120 years — it's become older, more diverse, and increasingly urbanised.
People are also having fewer children. Since 1901, the age group that recorded the largest decline as a proportion of the total population was children aged between five and nine.
The age group that's seen the biggest increase was the 60 to 64 cohort.
That's according to new demographic data issued by the Australian Bureau of Statistics (ABS).
So what are some of the changes to how Australia looks today compared to about 120 years ago?
Australia's population has grown almost every year since 1901
The ABS has noted a few key world events that have impacted population both negatively and positively since federation.
The only time the national population did not grow over the last 120 years was after World War I.
The Great Depression of the 30s, and WWII also negatively impacted population growth.
The global financial crisis in 2008 was followed by the highest net population growth in the country's history.
But unlike that crisis, the pandemic saw Australia experience the smallest population growth in more than a century as the impact of the world shutting down was felt in 2021.
The ABS has said Australia's population has aged at varying rates since 1901.
The government agency explained there were two distinct periods where the nation's population aged; the first period is between 1901 and 1944, while the second was between 1971 and 2021.
For example, the median age has gone from about 22.5 years in 1901 to about 38.4 in 2021.
Nine in 10 Australians live in urban areas
The bulk of Australia's population already were living in urbanised areas in 1901 but that number has continued to grow.
More than half of the population lived in urban areas at the beginning of federation but that has now grown to about 90 per cent.
The ABS has said the rate of urbanisation increased three times higher during the first half of the 20th century when compared to the second.
In terms of interstate migration there's been a clear winner, Queensland. The sunshine state enjoyed the biggest net gain, while New South Wales saw the highest loss.
The states that have seen losses with internal migrations over the last 40 years include NSW, Victoria and South Australia.
While, Queensland and Western Australia have seen gains in their population due to interstate migration.
Australia's migration patterns since federation
Australia's population has grown more diverse over time with overseas migration — excluding 2021 at the height of the COVID-19 pandemic — contributing more to population growth than natural growth since 2006.
The overseas-born proportion of the Australian population has increased from about 23 per cent in 1901 to about 29 per cent in 2021.
In 1901, the overwhelming majority of overseas-born Australian residents were from North-west Europe, particularly Ireland and the United Kingdom.
That's changed dramatically with migration patterns from the rest of the world, specifically from Asia increasing rapidly after the end of the White Australia Policy, which was replaced by a multiculturalism policy in 1973.
So what are the demographics of overseas-born population?
- People born in Italy and Greece made up about 40 to 60 per cent of Australian residents from the Southern and Eastern Europe region.
- Chinese-born Australian residents have made up between 38 and 87 per cent of residents born in North Asia.
- Indian-born Australian residents have represented about 49 to more than 90 per cent of residents born in Southern and Central Asia.
Australians are living longer, and having less children
Australia's fertility rate has decreased from about 3.1 births per woman in 1921 to about 1.7 in 2021.
That can be seen through the average age of a first-time mother which has increased from about 23.6 years in 1975 to about 30.5 years in 2020.
The baby boom between 1946 to 1961 led to the country's highest fertility in 1961 with about 3.5 births per woman.
That period also saw an increase in births from mothers aged under 30. But there's been a decline in the fertility rates for under 30s in most years since the 1970s.
Between 1979 and 2008 fertility rates for women over 30 increased substantially before starting to ease.
Infant mortality has also dropped from about 10.4 per cent of babies dying in their first year in 1901 to about 0.3 per cent in 2021.
Despite a decline in Australia's life expectancy for the first time in about 30 years, people are on average living about 26 years longer when compared to 1901.
Life expectancy for men increased from 55.2 to 81.3 years, while for women it was 58.8 to 85.4 years.
The probability of a person reaching their 100th birthday in 2021 when compared to 1901 has significantly increased.
Men are 143 times more likely to reach the milestone, while women are 82 times more likely.
First Nations communities not counted in the census until 1971
In the 1967 referendum, almost 91 per cent of Australians voted to change how Aboriginal and Torres Strait Islander people were referred to in the constitution.
As a result, First Nations people were counted for the first time in the 1971 census.
The numbers before that date include both counts and official estimates of the Indigenous population.
The ABS added that this data varied in accuracy, and "doesn't inherently represent the true population count".
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