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.

Key insight

In 2021, 5 to 9 year olds was the largest age group among residents in Blackett, accounting for 9.2% (329 people). This share was higher than Blacktown (C) (7.9%). Since 2016, the biggest change was in 65 to 69 year olds, which decreased by 69 people and 2.1 percentage points.

Section overview

Age structure - Five year age groups

Blackett - Total persons (Usual residence)

This table summarises five year age groups for Blackett in 2021 for persons, with comparison against Blacktown (C) and change since 2016.

Age structure - Five year age groups snapshot

2021 distribution by category for Blackett, with comparison markers for Blacktown (C).

Blackett
Blacktown (C)

0 to 4

2021 count

289

% of total

8.1%

Change from 2016

-1.7pp

5 to 9

2021 count

329

% of total

9.2%

Change from 2016

+0.3pp

10 to 14

2021 count

305

% of total

8.5%

Change from 2016

+0.9pp

15 to 19

2021 count

264

% of total

7.4%

Change from 2016

-1.2pp

20 to 24

2021 count

271

% of total

7.6%

Change from 2016

+0.6pp

25 to 29

2021 count

271

% of total

7.6%

Change from 2016

+0.8pp

30 to 34

2021 count

232

% of total

6.5%

Change from 2016

+0.7pp

35 to 39

2021 count

221

% of total

6.2%

Change from 2016

+0.4pp

40 to 44

2021 count

194

% of total

5.4%

Change from 2016

-0.4pp

45 to 49

2021 count

210

% of total

5.9%

Change from 2016

-0.6pp

50 to 54

2021 count

200

% of total

5.6%

Change from 2016

+0.2pp

55 to 59

2021 count

184

% of total

5.1%

Change from 2016

0.0pp

60 to 64

2021 count

165

% of total

4.6%

Change from 2016

+1.2pp

65 to 69

2021 count

119

% of total

3.3%

Change from 2016

-2.1pp

70 to 74

2021 count

140

% of total

3.9%

Change from 2016

+0.1pp

75 to 79

2021 count

105

% of total

2.9%

Change from 2016

+0.2pp

80 to 84

2021 count

76

% of total

2.1%

Change from 2016

+0.9pp

85 and over

2021 count

23

% of total

0.6%

Change from 2016

0.0pp

Data table

Five year age groups for Blackett. Age structure - Five year age groups. 2021 and 2016 counts, percentages, and change compared with Blacktown (C).

Five year age groups for Blackett. Age structure - Five year age groups. 2021 and 2016 counts, percentages, and change compared with Blacktown (C).
Five year age groups for Blackett. Age structure - Five year age groups. 2021 and 2016 counts, percentages, and change compared with Blacktown (C).
Category20212016Change
Count%Blacktown (C)%Count%Blacktown (C)%Countpp
0 to 42898.1%7.5%3409.8%8.0%-51-1.7pp
5 to 93299.2%7.9%3088.9%7.9%+21+0.3pp
10 to 143058.5%7.3%2647.6%6.9%+41+0.9pp
15 to 192647.4%6.1%2968.6%6.9%-32-1.2pp
20 to 242717.6%6.7%2417.0%6.8%+30+0.6pp
25 to 292717.6%7.0%2356.8%7.2%+36+0.8pp
30 to 342326.5%7.9%2005.8%8.3%+32+0.7pp
35 to 392216.2%9.2%1995.8%8.1%+22+0.4pp
40 to 441945.4%7.8%1995.8%7.2%-5-0.4pp
45 to 492105.9%6.4%2256.5%6.5%-15-0.6pp
50 to 542005.6%5.6%1875.4%6.0%+13+0.2pp
55 to 591845.1%5.1%1755.1%5.4%+90.0pp
60 to 641654.6%4.5%1173.4%4.6%+48+1.2pp
65 to 691193.3%3.7%1885.4%3.8%-69-2.1pp
70 to 741403.9%3.1%1323.8%2.5%+8+0.1pp
75 to 791052.9%1.9%932.7%1.7%+12+0.2pp
80 to 84762.1%1.2%431.2%1.1%+33+0.9pp
85 and over230.6%1.1%220.6%1.1%+10.0pp
Total3,586100.0%100.0%3,452100.0%100.0%+1340.0pp