Population
Service age groups
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.
Related topics
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.
Key insight
In 2021, Mid-life adults (35 to 49) was the most common category among residents in Cossack (NT), accounting for 20.4% (264 people). This share was similar to Katherine (T) (20.2%). Since 2016, the biggest change was in Young adults (18 to 24), which increased by 48 people and 3.4 percentage points.
Section overview
Age structure - Service age groups
Cossack (NT) - Total persons (Usual residence)
This table summarises service age groups for Cossack (NT) in 2021 for persons, with comparison against Katherine (T) and change since 2016.
Age structure - Service age groups snapshot
2021 distribution by category for Cossack (NT), with comparison markers for Katherine (T).
Early childhood (0 to 4)
Primary school age (5 to 11)
Secondary school age (12 to 17)
Young adults (18 to 24)
Early career adults (25 to 34)
Mid-life adults (35 to 49)
Pre-retirement adults (50 to 59)
Retirement transition (60 to 69)
Established seniors (70 to 84)
Advanced age (85 years and over)
Chart view
Age structure - Service age groups change
Absolute change in category counts between 2016 and 2021.
Early childhood (0 to 4)
+1
-0.3pp
Primary school age (5 to 11)
-2
-0.8pp
Secondary school age (12 to 17)
-40
-3.7pp
Young adults (18 to 24)
+48
+3.4pp
Early career adults (25 to 34)
+28
+1.6pp
Mid-life adults (35 to 49)
+20
+0.4pp
Pre-retirement adults (50 to 59)
-17
-2.3pp
Retirement transition (60 to 69)
+16
+0.6pp
Established seniors (70 to 84)
+31
+2.0pp
Advanced age (85 years and over)
-1
-0.1pp
Data table
Service age groups for Cossack (NT). Age structure - Service age groups. 2021 and 2016 counts, percentages, and change compared with Katherine (T).
| Category | 2021 | 2016 | Change | |||||
|---|---|---|---|---|---|---|---|---|
| Count | % | Katherine (T)% | Count | % | Katherine (T)% | Count | pp | |
| Early childhood (0 to 4) | 79 | 6.1% | 7.3% | 78 | 6.4% | 8.2% | +1 | -0.3pp |
| Primary school age (5 to 11) | 135 | 10.4% | 11.0% | 137 | 11.2% | 10.0% | -2 | -0.8pp |
| Secondary school age (12 to 17) | 98 | 7.6% | 7.3% | 138 | 11.3% | 8.3% | -40 | -3.7pp |
| Young adults (18 to 24) | 111 | 8.6% | 9.0% | 63 | 5.2% | 8.8% | +48 | +3.4pp |
| Early career adults (25 to 34) | 159 | 12.3% | 19.2% | 131 | 10.7% | 18.2% | +28 | +1.6pp |
| Mid-life adults (35 to 49) | 264 | 20.4% | 20.2% | 244 | 20.0% | 20.5% | +20 | +0.4pp |
| Pre-retirement adults (50 to 59) | 188 | 14.5% | 12.0% | 205 | 16.8% | 12.6% | -17 | -2.3pp |
| Retirement transition (60 to 69) | 154 | 11.9% | 8.8% | 138 | 11.3% | 8.6% | +16 | +0.6pp |
| Established seniors (70 to 84) | 104 | 8.0% | 4.8% | 73 | 6.0% | 4.6% | +31 | +2.0pp |
| Advanced age (85 years and over) | 6 | 0.5% | 0.5% | 7 | 0.6% | 0.5% | -1 | -0.1pp |
| Total | 1,293 | 100.0% | 100.0% | 1,223 | 100.0% | 100.0% | +70 | 0.0pp |