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, 35 to 39 year olds was the largest age group among residents in North Rocks (part), accounting for 7.6% (694 people). This share was lower than Parramatta (C) (10.2%). Since 2016, the biggest change was in 35 to 39 year olds, which increased by 539 people and 4 percentage points.
Section overview
Age structure - Five year age groups
North Rocks (part) - Total persons (Usual residence)
This table summarises five year age groups for North Rocks (part) in 2021 for persons, with comparison against Parramatta (C) and change since 2016.
Age structure - Five year age groups snapshot
2021 distribution by category for North Rocks (part), with comparison markers for Parramatta (C).
0 to 4
2021 count
486
% of total
5.3%
Change from 2016
+2.3pp
486
5.3%
+2.3pp
5 to 9
2021 count
656
% of total
7.2%
Change from 2016
+2.0pp
656
7.2%
+2.0pp
10 to 14
2021 count
658
% of total
7.2%
Change from 2016
+1.3pp
658
7.2%
+1.3pp
15 to 19
2021 count
529
% of total
5.8%
Change from 2016
+0.2pp
529
5.8%
+0.2pp
20 to 24
2021 count
514
% of total
5.6%
Change from 2016
+1.7pp
514
5.6%
+1.7pp
25 to 29
2021 count
475
% of total
5.2%
Change from 2016
+3.0pp
475
5.2%
+3.0pp
30 to 34
2021 count
540
% of total
5.9%
Change from 2016
+4.0pp
540
5.9%
+4.0pp
35 to 39
2021 count
694
% of total
7.6%
Change from 2016
+4.0pp
694
7.6%
+4.0pp
40 to 44
2021 count
688
% of total
7.5%
Change from 2016
+2.1pp
688
7.5%
+2.1pp
45 to 49
2021 count
684
% of total
7.5%
Change from 2016
+1.4pp
684
7.5%
+1.4pp
50 to 54
2021 count
573
% of total
6.3%
Change from 2016
+0.8pp
573
6.3%
+0.8pp
55 to 59
2021 count
541
% of total
5.9%
Change from 2016
+0.6pp
541
5.9%
+0.6pp
60 to 64
2021 count
512
% of total
5.6%
Change from 2016
+1.3pp
512
5.6%
+1.3pp
65 to 69
2021 count
437
% of total
4.8%
Change from 2016
-0.1pp
437
4.8%
-0.1pp
70 to 74
2021 count
461
% of total
5.0%
Change from 2016
-1.3pp
461
5.0%
-1.3pp
75 to 79
2021 count
371
% of total
4.1%
Change from 2016
-3.7pp
371
4.1%
-3.7pp
80 to 84
2021 count
206
% of total
2.3%
Change from 2016
-5.7pp
206
2.3%
-5.7pp
85 and over
2021 count
145
% of total
1.6%
Change from 2016
-14.5pp
145
1.6%
-14.5pp
Chart view
Age structure - Five year age groups change
Absolute change in category counts between 2016 and 2021.
0 to 4
+357
+2.3pp
5 to 9
+435
+2.0pp
10 to 14
+406
+1.3pp
15 to 19
+291
+0.2pp
20 to 24
+346
+1.7pp
25 to 29
+383
+3.0pp
30 to 34
+460
+4.0pp
35 to 39
+539
+4.0pp
40 to 44
+457
+2.1pp
45 to 49
+424
+1.4pp
50 to 54
+337
+0.8pp
55 to 59
+316
+0.6pp
60 to 64
+328
+1.3pp
65 to 69
+229
-0.1pp
70 to 74
+192
-1.3pp
75 to 79
+40
-3.7pp
80 to 84
-135
-5.7pp
85 and over
-539
-14.5pp
Data table
Five year age groups for North Rocks (part). Age structure - Five year age groups. 2021 and 2016 counts, percentages, and change compared with Parramatta (C).
| Category | 2021 | 2016 | Change | |||||
|---|---|---|---|---|---|---|---|---|
| Count | % | Parramatta (C)% | Count | % | Parramatta (C)% | Count | pp | |
| 0 to 4 | 486 | 5.3% | 6.2% | 129 | 3.0% | 7.3% | +357 | +2.3pp |
| 5 to 9 | 656 | 7.2% | 6.5% | 221 | 5.2% | 6.2% | +435 | +2.0pp |
| 10 to 14 | 658 | 7.2% | 5.4% | 252 | 5.9% | 4.9% | +406 | +1.3pp |
| 15 to 19 | 529 | 5.8% | 4.5% | 238 | 5.6% | 5.1% | +291 | +0.2pp |
| 20 to 24 | 514 | 5.6% | 6.6% | 168 | 3.9% | 6.6% | +346 | +1.7pp |
| 25 to 29 | 475 | 5.2% | 9.1% | 92 | 2.2% | 9.2% | +383 | +3.0pp |
| 30 to 34 | 540 | 5.9% | 10.3% | 80 | 1.9% | 11.1% | +460 | +4.0pp |
| 35 to 39 | 694 | 7.6% | 10.2% | 155 | 3.6% | 8.8% | +539 | +4.0pp |
| 40 to 44 | 688 | 7.5% | 7.5% | 231 | 5.4% | 7.0% | +457 | +2.1pp |
| 45 to 49 | 684 | 7.5% | 6.1% | 260 | 6.1% | 6.0% | +424 | +1.4pp |
| 50 to 54 | 573 | 6.3% | 5.3% | 236 | 5.5% | 5.8% | +337 | +0.8pp |
| 55 to 59 | 541 | 5.9% | 5.0% | 225 | 5.3% | 5.3% | +316 | +0.6pp |
| 60 to 64 | 512 | 5.6% | 4.6% | 184 | 4.3% | 4.6% | +328 | +1.3pp |
| 65 to 69 | 437 | 4.8% | 3.9% | 208 | 4.9% | 3.8% | +229 | -0.1pp |
| 70 to 74 | 461 | 5.0% | 3.1% | 269 | 6.3% | 2.9% | +192 | -1.3pp |
| 75 to 79 | 371 | 4.1% | 2.3% | 331 | 7.8% | 2.2% | +40 | -3.7pp |
| 80 to 84 | 206 | 2.3% | 1.6% | 341 | 8.0% | 1.6% | -135 | -5.7pp |
| 85 and over | 145 | 1.6% | 1.6% | 684 | 16.1% | 1.7% | -539 | -14.5pp |
| Total | 9,136 | 100.0% | 100.0% | 4,257 | 100.0% | 100.0% | +4,879 | 0.0pp |