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, 35 to 39 year olds was the largest age group among residents in Mortdale, accounting for 8.1% (867 people). This share was higher than Georges River (A) (7.2%). Since 2016, the biggest change was in 30 to 34 year olds, which decreased by 174 people and 1.9 percentage points.

Section overview

Age structure - Five year age groups

Mortdale - Total persons (Usual residence)

This table summarises five year age groups for Mortdale in 2021 for persons, with comparison against Georges River (A) and change since 2016.

Age structure - Five year age groups snapshot

2021 distribution by category for Mortdale, with comparison markers for Georges River (A).

Mortdale
Georges River (A)

0 to 4

2021 count

626

% of total

5.8%

Change from 2016

-0.9pp

5 to 9

2021 count

635

% of total

5.9%

Change from 2016

+0.3pp

10 to 14

2021 count

568

% of total

5.3%

Change from 2016

+0.3pp

15 to 19

2021 count

532

% of total

5.0%

Change from 2016

-0.1pp

20 to 24

2021 count

695

% of total

6.5%

Change from 2016

+0.3pp

25 to 29

2021 count

794

% of total

7.4%

Change from 2016

-0.5pp

30 to 34

2021 count

816

% of total

7.6%

Change from 2016

-1.9pp

35 to 39

2021 count

867

% of total

8.1%

Change from 2016

-0.6pp

40 to 44

2021 count

821

% of total

7.6%

Change from 2016

+0.2pp

45 to 49

2021 count

743

% of total

6.9%

Change from 2016

+0.3pp

50 to 54

2021 count

685

% of total

6.4%

Change from 2016

-0.6pp

55 to 59

2021 count

663

% of total

6.2%

Change from 2016

0.0pp

60 to 64

2021 count

614

% of total

5.7%

Change from 2016

+0.7pp

65 to 69

2021 count

520

% of total

4.8%

Change from 2016

+0.9pp

70 to 74

2021 count

413

% of total

3.8%

Change from 2016

+0.8pp

75 to 79

2021 count

282

% of total

2.6%

Change from 2016

+0.4pp

80 to 84

2021 count

186

% of total

1.7%

Change from 2016

+0.1pp

85 and over

2021 count

279

% of total

2.6%

Change from 2016

+0.1pp

Data table

Five year age groups for Mortdale. Age structure - Five year age groups. 2021 and 2016 counts, percentages, and change compared with Georges River (A).

Five year age groups for Mortdale. Age structure - Five year age groups. 2021 and 2016 counts, percentages, and change compared with Georges River (A).
Five year age groups for Mortdale. Age structure - Five year age groups. 2021 and 2016 counts, percentages, and change compared with Georges River (A).
Category20212016Change
Count%Georges River (A)%Count%Georges River (A)%Countpp
0 to 46265.8%5.0%7016.7%5.8%-75-0.9pp
5 to 96355.9%5.5%5855.6%5.6%+50+0.3pp
10 to 145685.3%5.4%5205.0%5.3%+48+0.3pp
15 to 195325.0%5.3%5295.1%6.1%+3-0.1pp
20 to 246956.5%7.6%6486.2%7.6%+47+0.3pp
25 to 297947.4%8.0%8187.9%8.7%-24-0.5pp
30 to 348167.6%7.5%9909.5%7.9%-174-1.9pp
35 to 398678.1%7.2%9078.7%6.6%-40-0.6pp
40 to 448217.6%6.3%7677.4%6.5%+54+0.2pp
45 to 497436.9%6.3%6886.6%6.5%+55+0.3pp
50 to 546856.4%6.2%7297.0%6.6%-44-0.6pp
55 to 596636.2%6.3%6466.2%6.1%+170.0pp
60 to 646145.7%5.9%5255.0%5.2%+89+0.7pp
65 to 695204.8%4.9%4033.9%4.5%+117+0.9pp
70 to 744133.8%4.2%3113.0%3.4%+102+0.8pp
75 to 792822.6%3.1%2312.2%2.7%+51+0.4pp
80 to 841861.7%2.3%1701.6%2.2%+16+0.1pp
85 and over2792.6%2.8%2622.5%2.6%+17+0.1pp
Total10,745100.0%100.0%10,419100.0%100.0%+3260.0pp