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 70 to 74 year olds, which increased by 88 people and 3 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
-1.0pp
99
3.3%
-1.0pp
5 to 9
2021 count
165
% of total
5.6%
Change from 2016
-2.4pp
165
5.6%
-2.4pp
10 to 14
2021 count
274
% of total
9.2%
Change from 2016
-1.0pp
274
9.2%
-1.0pp
15 to 19
2021 count
297
% of total
10.0%
Change from 2016
+1.8pp
297
10.0%
+1.8pp
20 to 24
2021 count
175
% of total
5.9%
Change from 2016
+1.6pp
175
5.9%
+1.6pp
25 to 29
2021 count
64
% of total
2.2%
Change from 2016
-0.1pp
64
2.2%
-0.1pp
30 to 34
2021 count
61
% of total
2.1%
Change from 2016
-0.2pp
61
2.1%
-0.2pp
35 to 39
2021 count
99
% of total
3.3%
Change from 2016
-1.4pp
99
3.3%
-1.4pp
40 to 44
2021 count
166
% of total
5.6%
Change from 2016
-2.2pp
166
5.6%
-2.2pp
45 to 49
2021 count
250
% of total
8.4%
Change from 2016
-1.2pp
250
8.4%
-1.2pp
50 to 54
2021 count
300
% of total
10.1%
Change from 2016
+1.8pp
300
10.1%
+1.8pp
55 to 59
2021 count
239
% of total
8.1%
Change from 2016
+0.9pp
239
8.1%
+0.9pp
60 to 64
2021 count
212
% of total
7.2%
Change from 2016
+1.3pp
212
7.2%
+1.3pp
65 to 69
2021 count
179
% of total
6.0%
Change from 2016
-0.7pp
179
6.0%
-0.7pp
70 to 74
2021 count
183
% of total
6.2%
Change from 2016
+3.0pp
183
6.2%
+3.0pp
75 to 79
2021 count
95
% of total
3.2%
Change from 2016
+1.1pp
95
3.2%
+1.1pp
80 to 84
2021 count
56
% of total
1.9%
Change from 2016
+0.3pp
56
1.9%
+0.3pp
85 and over
2021 count
64
% of total
2.2%
Change from 2016
-0.3pp
64
2.2%
-0.3pp
Chart view
Age structure - Five year age groups change
Absolute change in category counts between 2016 and 2021.
0 to 4
-28
-1.0pp
5 to 9
-69
-2.4pp
10 to 14
-25
-1.0pp
15 to 19
+55
+1.8pp
20 to 24
+49
+1.6pp
25 to 29
-3
-0.1pp
30 to 34
-6
-0.2pp
35 to 39
-38
-1.4pp
40 to 44
-63
-2.2pp
45 to 49
-31
-1.2pp
50 to 54
+57
+1.8pp
55 to 59
+28
+0.9pp
60 to 64
+38
+1.3pp
65 to 69
-18
-0.7pp
70 to 74
+88
+3.0pp
75 to 79
+34
+1.1pp
80 to 84
+10
+0.3pp
85 and over
-9
-0.3pp
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% | 127 | 4.3% | 6.6% | -28 | -1.0pp |
| 5 to 9 | 165 | 5.6% | 6.8% | 234 | 8.0% | 7.0% | -69 | -2.4pp |
| 10 to 14 | 274 | 9.2% | 6.8% | 299 | 10.2% | 5.8% | -25 | -1.0pp |
| 15 to 19 | 297 | 10.0% | 5.5% | 242 | 8.2% | 5.4% | +55 | +1.8pp |
| 20 to 24 | 175 | 5.9% | 5.2% | 126 | 4.3% | 6.0% | +49 | +1.6pp |
| 25 to 29 | 64 | 2.2% | 5.8% | 67 | 2.3% | 6.9% | -3 | -0.1pp |
| 30 to 34 | 61 | 2.1% | 6.6% | 67 | 2.3% | 8.3% | -6 | -0.2pp |
| 35 to 39 | 99 | 3.3% | 8.4% | 137 | 4.7% | 8.6% | -38 | -1.4pp |
| 40 to 44 | 166 | 5.6% | 8.4% | 229 | 7.8% | 8.1% | -63 | -2.2pp |
| 45 to 49 | 250 | 8.4% | 7.7% | 281 | 9.6% | 7.2% | -31 | -1.2pp |
| 50 to 54 | 300 | 10.1% | 6.6% | 243 | 8.3% | 6.3% | +57 | +1.8pp |
| 55 to 59 | 239 | 8.1% | 5.8% | 211 | 7.2% | 5.4% | +28 | +0.9pp |
| 60 to 64 | 212 | 7.2% | 5.0% | 174 | 5.9% | 4.8% | +38 | +1.3pp |
| 65 to 69 | 179 | 6.0% | 4.5% | 197 | 6.7% | 4.4% | -18 | -0.7pp |
| 70 to 74 | 183 | 6.2% | 4.1% | 95 | 3.2% | 2.9% | +88 | +3.0pp |
| 75 to 79 | 95 | 3.2% | 2.8% | 61 | 2.1% | 2.2% | +34 | +1.1pp |
| 80 to 84 | 56 | 1.9% | 2.0% | 46 | 1.6% | 1.8% | +10 | +0.3pp |
| 85 and over | 64 | 2.2% | 2.6% | 73 | 2.5% | 2.3% | -9 | -0.3pp |
| Total | 2,965 | 100.0% | 100.0% | 2,939 | 100.0% | 100.0% | +26 | 0.0pp |