Population
Five year age groups
About this topic
Five year age groups show the population in standard five-year cohorts from early childhood through older age. Because each band covers the same span of years, the topic gives a clear and comparable view of an area's age structure.
This topic is useful for identifying growth or decline in specific cohorts and for comparing age patterns across places and over time. For service planning, it is often read together with service age groups, household types, and dwelling types.
Interpretation notes
- Age is reported as at Census night, so the counts are a snapshot of the resident age structure at that point in time.
- Because each band covers the same five-year span, this topic is best for exact cohort comparison rather than service-planning life stages.
Related topics
Key insight
In 2021, 50 to 54 year olds was the largest age group among residents in Castlecrag, accounting for 10.1% (300 people). This share was higher than Willoughby (C) (6.6%). Since 2016, the biggest change was in 15 to 19 year olds, which increased by 278 people, while its share fell by 0.9 percentage points.
Section overview
Age structure - Five year age groups
Castlecrag - Total persons (Usual residence)
This table summarises five year age groups for Castlecrag in 2021 for persons, with comparison against Willoughby (C) and change since 2016.
Age structure - Five year age groups snapshot
2021 distribution by category for Castlecrag, with comparison markers for Willoughby (C).
0 to 4
2021 count
99
% of total
3.3%
Change from 2016
-0.1pp
99
3.3%
-0.1pp
5 to 9
2021 count
165
% of total
5.6%
Change from 2016
+0.5pp
165
5.6%
+0.5pp
10 to 14
2021 count
274
% of total
9.2%
Change from 2016
-0.5pp
274
9.2%
-0.5pp
15 to 19
2021 count
297
% of total
10.0%
Change from 2016
-0.9pp
297
10.0%
-0.9pp
20 to 24
2021 count
175
% of total
5.9%
Change from 2016
+0.8pp
175
5.9%
+0.8pp
25 to 29
2021 count
64
% of total
2.2%
Change from 2016
-1.2pp
64
2.2%
-1.2pp
30 to 34
2021 count
61
% of total
2.1%
Change from 2016
+2.1pp
61
2.1%
+2.1pp
35 to 39
2021 count
99
% of total
3.3%
Change from 2016
-1.8pp
99
3.3%
-1.8pp
40 to 44
2021 count
166
% of total
5.6%
Change from 2016
-0.1pp
166
5.6%
-0.1pp
45 to 49
2021 count
250
% of total
8.4%
Change from 2016
-0.2pp
250
8.4%
-0.2pp
50 to 54
2021 count
300
% of total
10.1%
Change from 2016
-3.6pp
300
10.1%
-3.6pp
55 to 59
2021 count
239
% of total
8.1%
Change from 2016
-2.8pp
239
8.1%
-2.8pp
60 to 64
2021 count
212
% of total
7.2%
Change from 2016
-1.9pp
212
7.2%
-1.9pp
65 to 69
2021 count
179
% of total
6.0%
Change from 2016
+6.0pp
179
6.0%
+6.0pp
70 to 74
2021 count
183
% of total
6.2%
Change from 2016
+4.5pp
183
6.2%
+4.5pp
75 to 79
2021 count
95
% of total
3.2%
Change from 2016
+0.9pp
95
3.2%
+0.9pp
80 to 84
2021 count
56
% of total
1.9%
Change from 2016
+1.9pp
56
1.9%
+1.9pp
85 and over
2021 count
64
% of total
2.2%
Change from 2016
+2.2pp
64
2.2%
+2.2pp
Chart view
Age structure - Five year age groups change
Absolute change in category counts between 2016 and 2021.
0 to 4
+93
-0.1pp
5 to 9
+156
+0.5pp
10 to 14
+257
-0.5pp
15 to 19
+278
-0.9pp
20 to 24
+166
+0.8pp
25 to 29
+58
-1.2pp
30 to 34
+61
+2.1pp
35 to 39
+90
-1.8pp
40 to 44
+156
-0.1pp
45 to 49
+235
-0.2pp
50 to 54
+276
-3.6pp
55 to 59
+220
-2.8pp
60 to 64
+196
-1.9pp
65 to 69
+179
+6.0pp
70 to 74
+180
+4.5pp
75 to 79
+91
+0.9pp
80 to 84
+56
+1.9pp
85 and over
+64
+2.2pp
Data table
Five year age groups for Castlecrag. Age structure - Five year age groups. 2021 and 2016 counts, percentages, and change compared with Willoughby (C).
| Category | 2021 | 2016 | Change | |||||
|---|---|---|---|---|---|---|---|---|
| Count | % | Willoughby (C)% | Count | % | Willoughby (C)% | Count | pp | |
| 0 to 4 | 99 | 3.3% | 5.2% | 6 | 3.4% | 6.6% | +93 | -0.1pp |
| 5 to 9 | 165 | 5.6% | 6.8% | 9 | 5.1% | 7.0% | +156 | +0.5pp |
| 10 to 14 | 274 | 9.2% | 6.8% | 17 | 9.7% | 5.8% | +257 | -0.5pp |
| 15 to 19 | 297 | 10.0% | 5.5% | 19 | 10.9% | 5.4% | +278 | -0.9pp |
| 20 to 24 | 175 | 5.9% | 5.2% | 9 | 5.1% | 6.0% | +166 | +0.8pp |
| 25 to 29 | 64 | 2.2% | 5.8% | 6 | 3.4% | 6.9% | +58 | -1.2pp |
| 30 to 34 | 61 | 2.1% | 6.6% | 0 | 0.0% | 8.3% | +61 | +2.1pp |
| 35 to 39 | 99 | 3.3% | 8.4% | 9 | 5.1% | 8.6% | +90 | -1.8pp |
| 40 to 44 | 166 | 5.6% | 8.4% | 10 | 5.7% | 8.1% | +156 | -0.1pp |
| 45 to 49 | 250 | 8.4% | 7.7% | 15 | 8.6% | 7.2% | +235 | -0.2pp |
| 50 to 54 | 300 | 10.1% | 6.6% | 24 | 13.7% | 6.3% | +276 | -3.6pp |
| 55 to 59 | 239 | 8.1% | 5.8% | 19 | 10.9% | 5.4% | +220 | -2.8pp |
| 60 to 64 | 212 | 7.2% | 5.0% | 16 | 9.1% | 4.8% | +196 | -1.9pp |
| 65 to 69 | 179 | 6.0% | 4.5% | 0 | 0.0% | 4.4% | +179 | +6.0pp |
| 70 to 74 | 183 | 6.2% | 4.1% | 3 | 1.7% | 2.9% | +180 | +4.5pp |
| 75 to 79 | 95 | 3.2% | 2.8% | 4 | 2.3% | 2.2% | +91 | +0.9pp |
| 80 to 84 | 56 | 1.9% | 2.0% | 0 | 0.0% | 1.8% | +56 | +1.9pp |
| 85 and over | 64 | 2.2% | 2.6% | 0 | 0.0% | 2.3% | +64 | +2.2pp |
| Total | 2,965 | 100.0% | 100.0% | 175 | 100.0% | 100.0% | +2,790 | 0.0pp |