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 Willunga, accounting for 19.6% (480 people). This share was higher than Onkaparinga (C) (19.2%). Since 2016, the biggest change was in Seniors (70 to 84), which increased by 90 people and 3 percentage points.
Section overview
Age structure - Service age groups
Willunga - Total persons (Usual residence)
This table summarises service age groups for Willunga in 2021 for persons, with comparison against Onkaparinga (C) and change since 2016.
Age structure - Service age groups snapshot
2021 distribution by category for Willunga, with comparison markers for Onkaparinga (C).
Babies and pre-schoolers (0 to 4)
2021 count
91
% of total
3.7%
Change from 2016
-1.4pp
91
3.7%
-1.4pp
Primary schoolers (5 to 11)
2021 count
241
% of total
9.9%
Change from 2016
+0.1pp
241
9.9%
+0.1pp
Secondary schoolers (12 to 17)
2021 count
174
% of total
7.1%
Change from 2016
-1.9pp
174
7.1%
-1.9pp
Tertiary education and independence (18 to 24)
2021 count
158
% of total
6.5%
Change from 2016
-0.5pp
158
6.5%
-0.5pp
Young workforce (25 to 34)
2021 count
157
% of total
6.4%
Change from 2016
-0.6pp
157
6.4%
-0.6pp
Parents and homebuilders (35 to 49)
2021 count
480
% of total
19.6%
Change from 2016
-2.4pp
480
19.6%
-2.4pp
Older workers and pre-retirees (50 to 59)
2021 count
365
% of total
14.9%
Change from 2016
+0.6pp
365
14.9%
+0.6pp
Empty nesters and retirees (60 to 69)
2021 count
372
% of total
15.2%
Change from 2016
+2.0pp
372
15.2%
+2.0pp
Seniors (70 to 84)
2021 count
343
% of total
14.0%
Change from 2016
+3.0pp
343
14.0%
+3.0pp
Elderly aged (85 and over)
2021 count
43
% of total
1.8%
Change from 2016
-0.4pp
43
1.8%
-0.4pp
Chart view
Age structure - Service age groups change
Absolute change in category counts between 2016 and 2021.
Babies and pre-schoolers (0 to 4)
-27
-1.4pp
Primary schoolers (5 to 11)
+14
+0.1pp
Secondary schoolers (12 to 17)
-34
-1.9pp
Tertiary education and independence (18 to 24)
-4
-0.5pp
Young workforce (25 to 34)
-5
-0.6pp
Parents and homebuilders (35 to 49)
-27
-2.4pp
Older workers and pre-retirees (50 to 59)
+34
+0.6pp
Empty nesters and retirees (60 to 69)
+68
+2.0pp
Seniors (70 to 84)
+90
+3.0pp
Elderly aged (85 and over)
-7
-0.4pp
Data table
Service age groups for Willunga. Age structure - Service age groups. 2021 and 2016 counts, percentages, and change compared with Onkaparinga (C).
| Category | 2021 | 2016 | Change | |||||
|---|---|---|---|---|---|---|---|---|
| Count | % | Onkaparinga (C)% | Count | % | Onkaparinga (C)% | Count | pp | |
| Babies and pre-schoolers (0 to 4) | 91 | 3.7% | 5.4% | 118 | 5.1% | 6.2% | -27 | -1.4pp |
| Primary schoolers (5 to 11) | 241 | 9.9% | 8.6% | 227 | 9.8% | 8.9% | +14 | +0.1pp |
| Secondary schoolers (12 to 17) | 174 | 7.1% | 7.3% | 208 | 9.0% | 7.5% | -34 | -1.9pp |
| Tertiary education and independence (18 to 24) | 158 | 6.5% | 7.9% | 162 | 7.0% | 8.4% | -4 | -0.5pp |
| Young workforce (25 to 34) | 157 | 6.4% | 12.2% | 162 | 7.0% | 12.4% | -5 | -0.6pp |
| Parents and homebuilders (35 to 49) | 480 | 19.6% | 19.2% | 507 | 22.0% | 19.7% | -27 | -2.4pp |
| Older workers and pre-retirees (50 to 59) | 365 | 14.9% | 13.1% | 331 | 14.3% | 13.3% | +34 | +0.6pp |
| Empty nesters and retirees (60 to 69) | 372 | 15.2% | 12.3% | 304 | 13.2% | 12.4% | +68 | +2.0pp |
| Seniors (70 to 84) | 343 | 14.0% | 11.8% | 253 | 11.0% | 9.1% | +90 | +3.0pp |
| Elderly aged (85 and over) | 43 | 1.8% | 2.2% | 50 | 2.2% | 2.1% | -7 | -0.4pp |
| Total | 2,445 | 100.0% | 100.0% | 2,308 | 100.0% | 100.0% | +137 | 0.0pp |