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, 55 to 59 year olds was the largest age group among residents in Keilor (part), accounting for 7.2% (425 people). This share was higher than Brimbank (C) (6.1%). Since 2016, the biggest change was in 75 to 79 year olds, which increased by 94 people and 1.6 percentage points.
Section overview
Age structure - Five year age groups
Keilor (part) - Total persons (Usual residence)
This table summarises five year age groups for Keilor (part) in 2021 for persons, with comparison against Brimbank (C) and change since 2016.
Age structure - Five year age groups snapshot
2021 distribution by category for Keilor (part), with comparison markers for Brimbank (C).
0 to 4
2021 count
270
% of total
4.6%
Change from 2016
+0.5pp
270
4.6%
+0.5pp
5 to 9
2021 count
299
% of total
5.1%
Change from 2016
-1.0pp
299
5.1%
-1.0pp
10 to 14
2021 count
374
% of total
6.3%
Change from 2016
-0.3pp
374
6.3%
-0.3pp
15 to 19
2021 count
378
% of total
6.4%
Change from 2016
-0.9pp
378
6.4%
-0.9pp
20 to 24
2021 count
332
% of total
5.6%
Change from 2016
-0.8pp
332
5.6%
-0.8pp
25 to 29
2021 count
277
% of total
4.7%
Change from 2016
+0.1pp
277
4.7%
+0.1pp
30 to 34
2021 count
286
% of total
4.8%
Change from 2016
+0.5pp
286
4.8%
+0.5pp
35 to 39
2021 count
300
% of total
5.1%
Change from 2016
-0.1pp
300
5.1%
-0.1pp
40 to 44
2021 count
351
% of total
5.9%
Change from 2016
0.0pp
351
5.9%
0.0pp
45 to 49
2021 count
376
% of total
6.4%
Change from 2016
-1.2pp
376
6.4%
-1.2pp
50 to 54
2021 count
423
% of total
7.2%
Change from 2016
-0.4pp
423
7.2%
-0.4pp
55 to 59
2021 count
425
% of total
7.2%
Change from 2016
+0.1pp
425
7.2%
+0.1pp
60 to 64
2021 count
407
% of total
6.9%
Change from 2016
+0.4pp
407
6.9%
+0.4pp
65 to 69
2021 count
346
% of total
5.9%
Change from 2016
-1.2pp
346
5.9%
-1.2pp
70 to 74
2021 count
379
% of total
6.4%
Change from 2016
+1.3pp
379
6.4%
+1.3pp
75 to 79
2021 count
282
% of total
4.8%
Change from 2016
+1.6pp
282
4.8%
+1.6pp
80 to 84
2021 count
192
% of total
3.3%
Change from 2016
+0.7pp
192
3.3%
+0.7pp
85 and over
2021 count
222
% of total
3.8%
Change from 2016
+0.6pp
222
3.8%
+0.6pp
Chart view
Age structure - Five year age groups change
Absolute change in category counts between 2016 and 2021.
0 to 4
+31
+0.5pp
5 to 9
-59
-1.0pp
10 to 14
-12
-0.3pp
15 to 19
-48
-0.9pp
20 to 24
-45
-0.8pp
25 to 29
+8
+0.1pp
30 to 34
+33
+0.5pp
35 to 39
-6
-0.1pp
40 to 44
+4
0.0pp
45 to 49
-66
-1.2pp
50 to 54
-21
-0.4pp
55 to 59
+9
+0.1pp
60 to 64
+27
+0.4pp
65 to 69
-72
-1.2pp
70 to 74
+81
+1.3pp
75 to 79
+94
+1.6pp
80 to 84
+39
+0.7pp
85 and over
+37
+0.6pp
Data table
Five year age groups for Keilor (part). Age structure - Five year age groups. 2021 and 2016 counts, percentages, and change compared with Brimbank (C).
| Category | 2021 | 2016 | Change | |||||
|---|---|---|---|---|---|---|---|---|
| Count | % | Brimbank (C)% | Count | % | Brimbank (C)% | Count | pp | |
| 0 to 4 | 270 | 4.6% | 5.6% | 239 | 4.1% | 6.7% | +31 | +0.5pp |
| 5 to 9 | 299 | 5.1% | 6.0% | 358 | 6.1% | 6.1% | -59 | -1.0pp |
| 10 to 14 | 374 | 6.3% | 5.7% | 386 | 6.6% | 5.7% | -12 | -0.3pp |
| 15 to 19 | 378 | 6.4% | 5.7% | 426 | 7.3% | 6.3% | -48 | -0.9pp |
| 20 to 24 | 332 | 5.6% | 6.9% | 377 | 6.4% | 7.8% | -45 | -0.8pp |
| 25 to 29 | 277 | 4.7% | 8.1% | 269 | 4.6% | 8.1% | +8 | +0.1pp |
| 30 to 34 | 286 | 4.8% | 7.6% | 253 | 4.3% | 8.0% | +33 | +0.5pp |
| 35 to 39 | 300 | 5.1% | 7.2% | 306 | 5.2% | 6.9% | -6 | -0.1pp |
| 40 to 44 | 351 | 5.9% | 6.4% | 347 | 5.9% | 6.6% | +4 | 0.0pp |
| 45 to 49 | 376 | 6.4% | 6.3% | 442 | 7.6% | 6.5% | -66 | -1.2pp |
| 50 to 54 | 423 | 7.2% | 6.3% | 444 | 7.6% | 6.3% | -21 | -0.4pp |
| 55 to 59 | 425 | 7.2% | 6.1% | 416 | 7.1% | 6.0% | +9 | +0.1pp |
| 60 to 64 | 407 | 6.9% | 5.8% | 380 | 6.5% | 5.4% | +27 | +0.4pp |
| 65 to 69 | 346 | 5.9% | 5.1% | 418 | 7.1% | 4.7% | -72 | -1.2pp |
| 70 to 74 | 379 | 6.4% | 4.3% | 298 | 5.1% | 3.3% | +81 | +1.3pp |
| 75 to 79 | 282 | 4.8% | 3.0% | 188 | 3.2% | 2.4% | +94 | +1.6pp |
| 80 to 84 | 192 | 3.3% | 2.0% | 153 | 2.6% | 1.7% | +39 | +0.7pp |
| 85 and over | 222 | 3.8% | 1.9% | 185 | 3.2% | 1.5% | +37 | +0.6pp |
| Total | 5,906 | 100.0% | 100.0% | 5,853 | 100.0% | 100.0% | +53 | 0.0pp |