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, 60 to 64 year olds was the largest age group among residents in Keilor Downs, accounting for 7.9% (783 people). This share was higher than Brimbank (C) (5.8%). Since 2016, the biggest change was in 70 to 74 year olds, which increased by 186 people and 1.9 percentage points.
Section overview
Age structure - Five year age groups
Keilor Downs - Total persons (Usual residence)
This table summarises five year age groups for Keilor Downs 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 Downs, with comparison markers for Brimbank (C).
0 to 4
2021 count
481
% of total
4.9%
Change from 2016
-0.5pp
481
4.9%
-0.5pp
5 to 9
2021 count
535
% of total
5.4%
Change from 2016
+0.1pp
535
5.4%
+0.1pp
10 to 14
2021 count
499
% of total
5.1%
Change from 2016
-0.8pp
499
5.1%
-0.8pp
15 to 19
2021 count
536
% of total
5.4%
Change from 2016
-0.5pp
536
5.4%
-0.5pp
20 to 24
2021 count
605
% of total
6.1%
Change from 2016
-1.1pp
605
6.1%
-1.1pp
25 to 29
2021 count
651
% of total
6.6%
Change from 2016
-0.7pp
651
6.6%
-0.7pp
30 to 34
2021 count
598
% of total
6.1%
Change from 2016
-0.1pp
598
6.1%
-0.1pp
35 to 39
2021 count
588
% of total
6.0%
Change from 2016
+0.3pp
588
6.0%
+0.3pp
40 to 44
2021 count
552
% of total
5.6%
Change from 2016
-0.3pp
552
5.6%
-0.3pp
45 to 49
2021 count
560
% of total
5.7%
Change from 2016
-0.4pp
560
5.7%
-0.4pp
50 to 54
2021 count
584
% of total
5.9%
Change from 2016
-1.0pp
584
5.9%
-1.0pp
55 to 59
2021 count
672
% of total
6.8%
Change from 2016
-1.2pp
672
6.8%
-1.2pp
60 to 64
2021 count
783
% of total
7.9%
Change from 2016
+0.2pp
783
7.9%
+0.2pp
65 to 69
2021 count
750
% of total
7.6%
Change from 2016
+1.5pp
750
7.6%
+1.5pp
70 to 74
2021 count
594
% of total
6.0%
Change from 2016
+1.9pp
594
6.0%
+1.9pp
75 to 79
2021 count
384
% of total
3.9%
Change from 2016
+0.8pp
384
3.9%
+0.8pp
80 to 84
2021 count
251
% of total
2.5%
Change from 2016
+0.4pp
251
2.5%
+0.4pp
85 and over
2021 count
209
% of total
2.1%
Change from 2016
+0.6pp
209
2.1%
+0.6pp
Chart view
Age structure - Five year age groups change
Absolute change in category counts between 2016 and 2021.
0 to 4
-60
-0.5pp
5 to 9
+9
+0.1pp
10 to 14
-86
-0.8pp
15 to 19
-57
-0.5pp
20 to 24
-115
-1.1pp
25 to 29
-74
-0.7pp
30 to 34
-21
-0.1pp
35 to 39
+19
+0.3pp
40 to 44
-39
-0.3pp
45 to 49
-52
-0.4pp
50 to 54
-103
-1.0pp
55 to 59
-124
-1.2pp
60 to 64
+14
+0.2pp
65 to 69
+137
+1.5pp
70 to 74
+186
+1.9pp
75 to 79
+76
+0.8pp
80 to 84
+41
+0.4pp
85 and over
+57
+0.6pp
Data table
Five year age groups for Keilor Downs. 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 | 481 | 4.9% | 5.6% | 541 | 5.4% | 6.7% | -60 | -0.5pp |
| 5 to 9 | 535 | 5.4% | 6.0% | 526 | 5.3% | 6.1% | +9 | +0.1pp |
| 10 to 14 | 499 | 5.1% | 5.7% | 585 | 5.9% | 5.7% | -86 | -0.8pp |
| 15 to 19 | 536 | 5.4% | 5.7% | 593 | 5.9% | 6.3% | -57 | -0.5pp |
| 20 to 24 | 605 | 6.1% | 6.9% | 720 | 7.2% | 7.8% | -115 | -1.1pp |
| 25 to 29 | 651 | 6.6% | 8.1% | 725 | 7.3% | 8.1% | -74 | -0.7pp |
| 30 to 34 | 598 | 6.1% | 7.6% | 619 | 6.2% | 8.0% | -21 | -0.1pp |
| 35 to 39 | 588 | 6.0% | 7.2% | 569 | 5.7% | 6.9% | +19 | +0.3pp |
| 40 to 44 | 552 | 5.6% | 6.4% | 591 | 5.9% | 6.6% | -39 | -0.3pp |
| 45 to 49 | 560 | 5.7% | 6.3% | 612 | 6.1% | 6.5% | -52 | -0.4pp |
| 50 to 54 | 584 | 5.9% | 6.3% | 687 | 6.9% | 6.3% | -103 | -1.0pp |
| 55 to 59 | 672 | 6.8% | 6.1% | 796 | 8.0% | 6.0% | -124 | -1.2pp |
| 60 to 64 | 783 | 7.9% | 5.8% | 769 | 7.7% | 5.4% | +14 | +0.2pp |
| 65 to 69 | 750 | 7.6% | 5.1% | 613 | 6.1% | 4.7% | +137 | +1.5pp |
| 70 to 74 | 594 | 6.0% | 4.3% | 408 | 4.1% | 3.3% | +186 | +1.9pp |
| 75 to 79 | 384 | 3.9% | 3.0% | 308 | 3.1% | 2.4% | +76 | +0.8pp |
| 80 to 84 | 251 | 2.5% | 2.0% | 210 | 2.1% | 1.7% | +41 | +0.4pp |
| 85 and over | 209 | 2.1% | 1.9% | 152 | 1.5% | 1.5% | +57 | +0.6pp |
| Total | 9,857 | 100.0% | 100.0% | 9,995 | 100.0% | 100.0% | -138 | 0.0pp |