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, 45 to 49 year olds was the largest age group among residents in Blackwood (SA), accounting for 7.4% (314 people). This share was higher than Mitcham (C) (7.1%). Since 2016, the biggest change was in 70 to 74 year olds, which increased by 53 people and 1.2 percentage points.
Section overview
Age structure - Five year age groups
Blackwood (SA) - Total persons (Usual residence)
This table summarises five year age groups for Blackwood (SA) in 2021 for persons, with comparison against Mitcham (C) and change since 2016.
Age structure - Five year age groups snapshot
2021 distribution by category for Blackwood (SA), with comparison markers for Mitcham (C).
0 to 4
2021 count
222
% of total
5.2%
Change from 2016
+0.2pp
222
5.2%
+0.2pp
5 to 9
2021 count
235
% of total
5.5%
Change from 2016
-0.5pp
235
5.5%
-0.5pp
10 to 14
2021 count
267
% of total
6.3%
Change from 2016
+0.7pp
267
6.3%
+0.7pp
15 to 19
2021 count
231
% of total
5.4%
Change from 2016
0.0pp
231
5.4%
0.0pp
20 to 24
2021 count
192
% of total
4.5%
Change from 2016
-1.2pp
192
4.5%
-1.2pp
25 to 29
2021 count
176
% of total
4.1%
Change from 2016
-1.0pp
176
4.1%
-1.0pp
30 to 34
2021 count
219
% of total
5.1%
Change from 2016
0.0pp
219
5.1%
0.0pp
35 to 39
2021 count
268
% of total
6.3%
Change from 2016
+0.4pp
268
6.3%
+0.4pp
40 to 44
2021 count
274
% of total
6.4%
Change from 2016
-0.4pp
274
6.4%
-0.4pp
45 to 49
2021 count
314
% of total
7.4%
Change from 2016
+0.3pp
314
7.4%
+0.3pp
50 to 54
2021 count
273
% of total
6.4%
Change from 2016
-0.5pp
273
6.4%
-0.5pp
55 to 59
2021 count
289
% of total
6.8%
Change from 2016
0.0pp
289
6.8%
0.0pp
60 to 64
2021 count
277
% of total
6.5%
Change from 2016
+0.3pp
277
6.5%
+0.3pp
65 to 69
2021 count
265
% of total
6.2%
Change from 2016
0.0pp
265
6.2%
0.0pp
70 to 74
2021 count
285
% of total
6.7%
Change from 2016
+1.2pp
285
6.7%
+1.2pp
75 to 79
2021 count
194
% of total
4.5%
Change from 2016
+0.7pp
194
4.5%
+0.7pp
80 to 84
2021 count
148
% of total
3.5%
Change from 2016
+0.7pp
148
3.5%
+0.7pp
85 and over
2021 count
139
% of total
3.3%
Change from 2016
0.0pp
139
3.3%
0.0pp
Chart view
Age structure - Five year age groups change
Absolute change in category counts between 2016 and 2021.
0 to 4
+14
+0.2pp
5 to 9
-17
-0.5pp
10 to 14
+31
+0.7pp
15 to 19
+6
0.0pp
20 to 24
-46
-1.2pp
25 to 29
-38
-1.0pp
30 to 34
+6
0.0pp
35 to 39
+22
+0.4pp
40 to 44
-9
-0.4pp
45 to 49
+19
+0.3pp
50 to 54
-14
-0.5pp
55 to 59
+3
0.0pp
60 to 64
+19
+0.3pp
65 to 69
+5
0.0pp
70 to 74
+53
+1.2pp
75 to 79
+36
+0.7pp
80 to 84
+33
+0.7pp
85 and over
+3
0.0pp
Data table
Five year age groups for Blackwood (SA). Age structure - Five year age groups. 2021 and 2016 counts, percentages, and change compared with Mitcham (C).
| Category | 2021 | 2016 | Change | |||||
|---|---|---|---|---|---|---|---|---|
| Count | % | Mitcham (C)% | Count | % | Mitcham (C)% | Count | pp | |
| 0 to 4 | 222 | 5.2% | 4.9% | 208 | 5.0% | 5.3% | +14 | +0.2pp |
| 5 to 9 | 235 | 5.5% | 6.0% | 252 | 6.0% | 6.2% | -17 | -0.5pp |
| 10 to 14 | 267 | 6.3% | 6.4% | 236 | 5.6% | 6.1% | +31 | +0.7pp |
| 15 to 19 | 231 | 5.4% | 6.4% | 225 | 5.4% | 6.6% | +6 | 0.0pp |
| 20 to 24 | 192 | 4.5% | 6.0% | 238 | 5.7% | 6.4% | -46 | -1.2pp |
| 25 to 29 | 176 | 4.1% | 5.1% | 214 | 5.1% | 5.1% | -38 | -1.0pp |
| 30 to 34 | 219 | 5.1% | 5.4% | 213 | 5.1% | 5.6% | +6 | 0.0pp |
| 35 to 39 | 268 | 6.3% | 6.2% | 246 | 5.9% | 6.0% | +22 | +0.4pp |
| 40 to 44 | 274 | 6.4% | 6.6% | 283 | 6.8% | 6.9% | -9 | -0.4pp |
| 45 to 49 | 314 | 7.4% | 7.1% | 295 | 7.1% | 7.1% | +19 | +0.3pp |
| 50 to 54 | 273 | 6.4% | 6.7% | 287 | 6.9% | 6.7% | -14 | -0.5pp |
| 55 to 59 | 289 | 6.8% | 6.2% | 286 | 6.8% | 6.7% | +3 | 0.0pp |
| 60 to 64 | 277 | 6.5% | 6.1% | 258 | 6.2% | 5.8% | +19 | +0.3pp |
| 65 to 69 | 265 | 6.2% | 5.4% | 260 | 6.2% | 5.7% | +5 | 0.0pp |
| 70 to 74 | 285 | 6.7% | 5.4% | 232 | 5.5% | 4.6% | +53 | +1.2pp |
| 75 to 79 | 194 | 4.5% | 4.1% | 158 | 3.8% | 3.4% | +36 | +0.7pp |
| 80 to 84 | 148 | 3.5% | 2.8% | 115 | 2.8% | 2.5% | +33 | +0.7pp |
| 85 and over | 139 | 3.3% | 3.3% | 136 | 3.3% | 3.4% | +3 | 0.0pp |
| Total | 4,266 | 100.0% | 100.0% | 4,181 | 100.0% | 100.0% | +85 | 0.0pp |