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 25 to 29 year olds, which increased by 185 people and 1.6 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
5 to 9
10 to 14
15 to 19
20 to 24
25 to 29
30 to 34
35 to 39
40 to 44
45 to 49
50 to 54
55 to 59
60 to 64
65 to 69
70 to 74
75 to 79
80 to 84
85 and over
Chart view
Age structure - Five year age groups change
Absolute change in category counts between 2016 and 2021.
0 to 4
-40
-1.3pp
5 to 9
+74
-0.1pp
10 to 14
+141
+0.7pp
15 to 19
+47
-0.3pp
20 to 24
+82
+0.2pp
25 to 29
+185
+1.6pp
30 to 34
+66
-0.1pp
35 to 39
+149
+0.8pp
40 to 44
+104
+0.2pp
45 to 49
+146
+0.7pp
50 to 54
+26
-0.6pp
55 to 59
+17
-0.7pp
60 to 64
+48
-0.2pp
65 to 69
-52
-1.3pp
70 to 74
+45
-0.2pp
75 to 79
+117
+0.9pp
80 to 84
+75
+0.7pp
85 and over
-5
-0.3pp
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% | 526 | 6.6% | 7.3% | -40 | -1.3pp |
| 5 to 9 | 656 | 7.2% | 6.5% | 582 | 7.3% | 6.2% | +74 | -0.1pp |
| 10 to 14 | 658 | 7.2% | 5.4% | 517 | 6.5% | 4.9% | +141 | +0.7pp |
| 15 to 19 | 529 | 5.8% | 4.5% | 482 | 6.1% | 5.1% | +47 | -0.3pp |
| 20 to 24 | 514 | 5.6% | 6.6% | 432 | 5.4% | 6.6% | +82 | +0.2pp |
| 25 to 29 | 475 | 5.2% | 9.1% | 290 | 3.6% | 9.2% | +185 | +1.6pp |
| 30 to 34 | 540 | 5.9% | 10.3% | 474 | 6.0% | 11.1% | +66 | -0.1pp |
| 35 to 39 | 694 | 7.6% | 10.2% | 545 | 6.8% | 8.8% | +149 | +0.8pp |
| 40 to 44 | 688 | 7.5% | 7.5% | 584 | 7.3% | 7.0% | +104 | +0.2pp |
| 45 to 49 | 684 | 7.5% | 6.1% | 538 | 6.8% | 6.0% | +146 | +0.7pp |
| 50 to 54 | 573 | 6.3% | 5.3% | 547 | 6.9% | 5.8% | +26 | -0.6pp |
| 55 to 59 | 541 | 5.9% | 5.0% | 524 | 6.6% | 5.3% | +17 | -0.7pp |
| 60 to 64 | 512 | 5.6% | 4.6% | 464 | 5.8% | 4.6% | +48 | -0.2pp |
| 65 to 69 | 437 | 4.8% | 3.9% | 489 | 6.1% | 3.8% | -52 | -1.3pp |
| 70 to 74 | 461 | 5.0% | 3.1% | 416 | 5.2% | 2.9% | +45 | -0.2pp |
| 75 to 79 | 371 | 4.1% | 2.3% | 254 | 3.2% | 2.2% | +117 | +0.9pp |
| 80 to 84 | 206 | 2.3% | 1.6% | 131 | 1.6% | 1.6% | +75 | +0.7pp |
| 85 and over | 145 | 1.6% | 1.6% | 150 | 1.9% | 1.7% | -5 | -0.3pp |
| Total | 9,136 | 100.0% | 100.0% | 7,965 | 100.0% | 100.0% | +1,171 | 0.0pp |