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, 65 to 69 year olds was the largest age group among residents in Irwin (S), accounting for 9.8% (361 people). This share was higher than Regional WA (5.7%). Since 2016, the biggest change was in 75 to 79 year olds, which increased by 65 people and 1.6 percentage points.
Section overview
Age structure - Five year age groups
Irwin (S) - Total persons (Usual residence)
This table summarises five year age groups for Irwin (S) in 2021 for persons, with comparison against Regional WA and change since 2016.
Age structure - Five year age groups snapshot
2021 distribution by category for Irwin (S), with comparison markers for Regional WA.
0 to 4
2021 count
139
% of total
3.8%
Change from 2016
-0.9pp
139
3.8%
-0.9pp
5 to 9
2021 count
172
% of total
4.7%
Change from 2016
-1.9pp
172
4.7%
-1.9pp
10 to 14
2021 count
239
% of total
6.5%
Change from 2016
+0.5pp
239
6.5%
+0.5pp
15 to 19
2021 count
179
% of total
4.9%
Change from 2016
-0.5pp
179
4.9%
-0.5pp
20 to 24
2021 count
126
% of total
3.4%
Change from 2016
+0.7pp
126
3.4%
+0.7pp
25 to 29
2021 count
104
% of total
2.8%
Change from 2016
-0.1pp
104
2.8%
-0.1pp
30 to 34
2021 count
114
% of total
3.1%
Change from 2016
-1.6pp
114
3.1%
-1.6pp
35 to 39
2021 count
174
% of total
4.7%
Change from 2016
0.0pp
174
4.7%
0.0pp
40 to 44
2021 count
181
% of total
4.9%
Change from 2016
-1.0pp
181
4.9%
-1.0pp
45 to 49
2021 count
233
% of total
6.3%
Change from 2016
+0.3pp
233
6.3%
+0.3pp
50 to 54
2021 count
241
% of total
6.5%
Change from 2016
-1.1pp
241
6.5%
-1.1pp
55 to 59
2021 count
317
% of total
8.6%
Change from 2016
+1.2pp
317
8.6%
+1.2pp
60 to 64
2021 count
336
% of total
9.1%
Change from 2016
-0.1pp
336
9.1%
-0.1pp
65 to 69
2021 count
361
% of total
9.8%
Change from 2016
+1.0pp
361
9.8%
+1.0pp
70 to 74
2021 count
313
% of total
8.5%
Change from 2016
+1.3pp
313
8.5%
+1.3pp
75 to 79
2021 count
222
% of total
6.0%
Change from 2016
+1.6pp
222
6.0%
+1.6pp
80 to 84
2021 count
143
% of total
3.9%
Change from 2016
+1.2pp
143
3.9%
+1.2pp
85 and over
2021 count
78
% of total
2.1%
Change from 2016
-0.3pp
78
2.1%
-0.3pp
Chart view
Age structure - Five year age groups change
Absolute change in category counts between 2016 and 2021.
0 to 4
-28
-0.9pp
5 to 9
-62
-1.9pp
10 to 14
+25
+0.5pp
15 to 19
-15
-0.5pp
20 to 24
+28
+0.7pp
25 to 29
-1
-0.1pp
30 to 34
-52
-1.6pp
35 to 39
+6
0.0pp
40 to 44
-29
-1.0pp
45 to 49
+18
+0.3pp
50 to 54
-31
-1.1pp
55 to 59
+54
+1.2pp
60 to 64
+7
-0.1pp
65 to 69
+46
+1.0pp
70 to 74
+57
+1.3pp
75 to 79
+65
+1.6pp
80 to 84
+45
+1.2pp
85 and over
-9
-0.3pp
Data table
Five year age groups for Irwin (S). Age structure - Five year age groups. 2021 and 2016 counts, percentages, and change compared with Regional WA.
| Category | 2021 | 2016 | Change | |||||
|---|---|---|---|---|---|---|---|---|
| Count | % | Regional WA% | Count | % | Regional WA% | Count | pp | |
| 0 to 4 | 139 | 3.8% | 6.0% | 167 | 4.7% | 6.6% | -28 | -0.9pp |
| 5 to 9 | 172 | 4.7% | 6.7% | 234 | 6.6% | 7.1% | -62 | -1.9pp |
| 10 to 14 | 239 | 6.5% | 6.7% | 214 | 6.0% | 6.5% | +25 | +0.5pp |
| 15 to 19 | 179 | 4.9% | 5.5% | 194 | 5.4% | 5.7% | -15 | -0.5pp |
| 20 to 24 | 126 | 3.4% | 4.8% | 98 | 2.7% | 5.0% | +28 | +0.7pp |
| 25 to 29 | 104 | 2.8% | 5.9% | 105 | 2.9% | 6.5% | -1 | -0.1pp |
| 30 to 34 | 114 | 3.1% | 6.6% | 166 | 4.7% | 7.1% | -52 | -1.6pp |
| 35 to 39 | 174 | 4.7% | 6.8% | 168 | 4.7% | 6.7% | +6 | 0.0pp |
| 40 to 44 | 181 | 4.9% | 6.4% | 210 | 5.9% | 7.0% | -29 | -1.0pp |
| 45 to 49 | 233 | 6.3% | 6.6% | 215 | 6.0% | 7.2% | +18 | +0.3pp |
| 50 to 54 | 241 | 6.5% | 6.9% | 272 | 7.6% | 7.1% | -31 | -1.1pp |
| 55 to 59 | 317 | 8.6% | 6.8% | 263 | 7.4% | 6.9% | +54 | +1.2pp |
| 60 to 64 | 336 | 9.1% | 6.7% | 329 | 9.2% | 6.0% | +7 | -0.1pp |
| 65 to 69 | 361 | 9.8% | 5.7% | 315 | 8.8% | 5.3% | +46 | +1.0pp |
| 70 to 74 | 313 | 8.5% | 4.9% | 256 | 7.2% | 3.6% | +57 | +1.3pp |
| 75 to 79 | 222 | 6.0% | 3.2% | 157 | 4.4% | 2.6% | +65 | +1.6pp |
| 80 to 84 | 143 | 3.9% | 2.0% | 98 | 2.7% | 1.6% | +45 | +1.2pp |
| 85 and over | 78 | 2.1% | 1.7% | 87 | 2.4% | 1.5% | -9 | -0.3pp |
| Total | 3,680 | 100.0% | 100.0% | 3,569 | 100.0% | 100.0% | +111 | 0.0pp |