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 Two Rocks, accounting for 19.3% (736 people). This share was lower than Wanneroo (C) (21.7%). Since 2016, the biggest change was in Older workers and pre-retirees (50 to 59), which increased by 247 people and 2 percentage points.
Section overview
Age structure - Service age groups
Two Rocks - Total persons (Usual residence)
This table summarises service age groups for Two Rocks in 2021 for persons, with comparison against Wanneroo (C) and change since 2016.
Age structure - Service age groups snapshot
2021 distribution by category for Two Rocks, with comparison markers for Wanneroo (C).
Babies and pre-schoolers (0 to 4)
2021 count
253
% of total
6.6%
Change from 2016
-1.8pp
253
6.6%
-1.8pp
Primary schoolers (5 to 11)
2021 count
462
% of total
12.1%
Change from 2016
-1.5pp
462
12.1%
-1.5pp
Secondary schoolers (12 to 17)
2021 count
304
% of total
8.0%
Change from 2016
-2.1pp
304
8.0%
-2.1pp
Tertiary education and independence (18 to 24)
2021 count
237
% of total
6.2%
Change from 2016
-0.6pp
237
6.2%
-0.6pp
Young workforce (25 to 34)
2021 count
431
% of total
11.3%
Change from 2016
-0.9pp
431
11.3%
-0.9pp
Parents and homebuilders (35 to 49)
2021 count
736
% of total
19.3%
Change from 2016
-3.0pp
736
19.3%
-3.0pp
Older workers and pre-retirees (50 to 59)
2021 count
565
% of total
14.8%
Change from 2016
+2.0pp
565
14.8%
+2.0pp
Empty nesters and retirees (60 to 69)
2021 count
463
% of total
12.1%
Change from 2016
+1.7pp
463
12.1%
+1.7pp
Seniors (70 to 84)
2021 count
353
% of total
9.2%
Change from 2016
+4.2pp
353
9.2%
+4.2pp
Elderly aged (85 and over)
2021 count
34
% of total
0.9%
Change from 2016
+0.7pp
34
0.9%
+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)
+45
-1.8pp
Primary schoolers (5 to 11)
+124
-1.5pp
Secondary schoolers (12 to 17)
+53
-2.1pp
Tertiary education and independence (18 to 24)
+69
-0.6pp
Young workforce (25 to 34)
+128
-0.9pp
Parents and homebuilders (35 to 49)
+184
-3.0pp
Older workers and pre-retirees (50 to 59)
+247
+2.0pp
Empty nesters and retirees (60 to 69)
+204
+1.7pp
Seniors (70 to 84)
+228
+4.2pp
Elderly aged (85 and over)
+29
+0.7pp
Data table
Service age groups for Two Rocks. Age structure - Service age groups. 2021 and 2016 counts, percentages, and change compared with Wanneroo (C).
| Category | 2021 | 2016 | Change | |||||
|---|---|---|---|---|---|---|---|---|
| Count | % | Wanneroo (C)% | Count | % | Wanneroo (C)% | Count | pp | |
| Babies and pre-schoolers (0 to 4) | 253 | 6.6% | 7.1% | 208 | 8.4% | 8.0% | +45 | -1.8pp |
| Primary schoolers (5 to 11) | 462 | 12.1% | 10.6% | 338 | 13.6% | 10.8% | +124 | -1.5pp |
| Secondary schoolers (12 to 17) | 304 | 8.0% | 8.5% | 251 | 10.1% | 8.5% | +53 | -2.1pp |
| Tertiary education and independence (18 to 24) | 237 | 6.2% | 9.0% | 168 | 6.8% | 9.6% | +69 | -0.6pp |
| Young workforce (25 to 34) | 431 | 11.3% | 13.9% | 303 | 12.2% | 15.7% | +128 | -0.9pp |
| Parents and homebuilders (35 to 49) | 736 | 19.3% | 21.7% | 552 | 22.3% | 22.4% | +184 | -3.0pp |
| Older workers and pre-retirees (50 to 59) | 565 | 14.8% | 12.5% | 318 | 12.8% | 11.2% | +247 | +2.0pp |
| Empty nesters and retirees (60 to 69) | 463 | 12.1% | 8.5% | 259 | 10.4% | 7.4% | +204 | +1.7pp |
| Seniors (70 to 84) | 353 | 9.2% | 7.0% | 125 | 5.0% | 5.4% | +228 | +4.2pp |
| Elderly aged (85 and over) | 34 | 0.9% | 1.3% | 5 | 0.2% | 1.0% | +29 | +0.7pp |
| Total | 3,822 | 100.0% | 100.0% | 2,479 | 100.0% | 100.0% | +1,343 | 0.0pp |