Population
Service age groups
About this topic
Service age groups divide the population into broad life-stage bands such as children, young adults, working-age adults, and older people. The groupings are designed to reflect typical demand for age-based services and facilities rather than exact five-year cohorts.
This view is useful for planning childcare, schools, recreation, aged services, and other community infrastructure. It works best alongside five year age groups, household type, and dwelling data, which add more detail about who is living in an area and how needs may change over time.
Interpretation notes
- This is a derived grouping rather than a direct Census question, so the age bands are planning-oriented summaries built from standard age data.
- Percentages relate to the total population; use five year age groups when exact cohort detail matters.
Related topics
Key insight
In 2021, Parents and homebuilders (35 to 49) was the most common category among residents in Holdfast Bay (C), accounting for 18% (6,748 people). This share was lower than Greater Adelaide (19.6%). Since 2016, the biggest change was in Seniors (70 to 84), which increased by 1,423 people and 3.1 percentage points.
Section overview
Age structure - Service age groups
Holdfast Bay (C) - Total persons (Usual residence)
This table summarises service age groups for Holdfast Bay (C) in 2021 for persons, with comparison against Greater Adelaide and change since 2016.
Age structure - Service age groups snapshot
2021 distribution by category for Holdfast Bay (C), with comparison markers for Greater Adelaide.
Babies and pre-schoolers (0 to 4)
2021 count
1,418
% of total
3.8%
Change from 2016
-0.5pp
1,418
3.8%
-0.5pp
Primary schoolers (5 to 11)
2021 count
2,407
% of total
6.4%
Change from 2016
0.0pp
2,407
6.4%
0.0pp
Secondary schoolers (12 to 17)
2021 count
2,321
% of total
6.2%
Change from 2016
+0.5pp
2,321
6.2%
+0.5pp
Tertiary education and independence (18 to 24)
2021 count
2,686
% of total
7.2%
Change from 2016
-0.8pp
2,686
7.2%
-0.8pp
Young workforce (25 to 34)
2021 count
3,975
% of total
10.6%
Change from 2016
-1.0pp
3,975
10.6%
-1.0pp
Parents and homebuilders (35 to 49)
2021 count
6,748
% of total
18.0%
Change from 2016
-0.2pp
6,748
18.0%
-0.2pp
Older workers and pre-retirees (50 to 59)
2021 count
5,053
% of total
13.5%
Change from 2016
-1.1pp
5,053
13.5%
-1.1pp
Empty nesters and retirees (60 to 69)
2021 count
5,631
% of total
15.0%
Change from 2016
+0.8pp
5,631
15.0%
+0.8pp
Seniors (70 to 84)
2021 count
5,731
% of total
15.3%
Change from 2016
+3.1pp
5,731
15.3%
+3.1pp
Elderly aged (85 and over)
2021 count
1,538
% of total
4.1%
Change from 2016
-0.7pp
1,538
4.1%
-0.7pp
Chart view
Age structure - Service age groups change
Absolute change in category counts between 2016 and 2021.
Babies and pre-schoolers (0 to 4)
-98
-0.5pp
Primary schoolers (5 to 11)
+132
0.0pp
Secondary schoolers (12 to 17)
+291
+0.5pp
Tertiary education and independence (18 to 24)
-141
-0.8pp
Young workforce (25 to 34)
-125
-1.0pp
Parents and homebuilders (35 to 49)
+299
-0.2pp
Older workers and pre-retirees (50 to 59)
-105
-1.1pp
Empty nesters and retirees (60 to 69)
+609
+0.8pp
Seniors (70 to 84)
+1,423
+3.1pp
Elderly aged (85 and over)
-152
-0.7pp
Data table
Service age groups for Holdfast Bay (C). Age structure - Service age groups. 2021 and 2016 counts, percentages, and change compared with Greater Adelaide.
| Category | 2021 | 2016 | Change | |||||
|---|---|---|---|---|---|---|---|---|
| Count | % | Greater Adelaide% | Count | % | Greater Adelaide% | Count | pp | |
| Babies and pre-schoolers (0 to 4) | 1,418 | 3.8% | 5.4% | 1,516 | 4.3% | 5.9% | -98 | -0.5pp |
| Primary schoolers (5 to 11) | 2,407 | 6.4% | 8.2% | 2,275 | 6.4% | 8.2% | +132 | 0.0pp |
| Secondary schoolers (12 to 17) | 2,321 | 6.2% | 6.9% | 2,030 | 5.7% | 6.9% | +291 | +0.5pp |
| Tertiary education and independence (18 to 24) | 2,686 | 7.2% | 8.8% | 2,827 | 8.0% | 9.5% | -141 | -0.8pp |
| Young workforce (25 to 34) | 3,975 | 10.6% | 14.0% | 4,100 | 11.6% | 13.8% | -125 | -1.0pp |
| Parents and homebuilders (35 to 49) | 6,748 | 18.0% | 19.6% | 6,449 | 18.2% | 19.7% | +299 | -0.2pp |
| Older workers and pre-retirees (50 to 59) | 5,053 | 13.5% | 12.6% | 5,158 | 14.6% | 13.1% | -105 | -1.1pp |
| Empty nesters and retirees (60 to 69) | 5,631 | 15.0% | 11.2% | 5,022 | 14.2% | 11.1% | +609 | +0.8pp |
| Seniors (70 to 84) | 5,731 | 15.3% | 10.7% | 4,308 | 12.2% | 9.3% | +1,423 | +3.1pp |
| Elderly aged (85 and over) | 1,538 | 4.1% | 2.6% | 1,690 | 4.8% | 2.6% | -152 | -0.7pp |
| Total | 37,543 | 100.0% | 100.0% | 35,360 | 100.0% | 100.0% | +2,183 | 0.0pp |