Population

Service age groups

About this topic

Service age groups divide the population into broad life-stage bands such as children, young adults, working-age adults, and older people. The groupings are designed to reflect typical demand for age-based services and facilities rather than exact five-year cohorts.

This view is useful for planning childcare, schools, recreation, aged services, and other community infrastructure. It works best alongside five year age groups, household type, and dwelling data, which add more detail about who is living in an area and how needs may change over time.

Interpretation notes

  • This is a derived grouping rather than a direct Census question, so the age bands are planning-oriented summaries built from standard age data.
  • Percentages relate to the total population; use five year age groups when exact cohort detail matters.

Key insight

In 2021, Parents and homebuilders (35 to 49) was the most common category among residents in North St Marys, accounting for 17.7% (729 people). This share was lower than Penrith (C) (21%). Since 2016, the biggest change was in Young workforce (25 to 34), which increased by 89 people and 1.5 percentage points.

Section overview

Age structure - Service age groups

North St Marys - Total persons (Usual residence)

This table summarises service age groups for North St Marys in 2021 for persons, with comparison against Penrith (C) and change since 2016.

Age structure - Service age groups snapshot

2021 distribution by category for North St Marys, with comparison markers for Penrith (C).

North St Marys
Penrith (C)

Babies and pre-schoolers (0 to 4)

2021 count

269

% of total

6.5%

Change from 2016

-1.4pp

Primary schoolers (5 to 11)

2021 count

440

% of total

10.7%

Change from 2016

-0.3pp

Secondary schoolers (12 to 17)

2021 count

344

% of total

8.3%

Change from 2016

+1.3pp

Tertiary education and independence (18 to 24)

2021 count

396

% of total

9.6%

Change from 2016

-1.3pp

Young workforce (25 to 34)

2021 count

614

% of total

14.9%

Change from 2016

+1.5pp

Parents and homebuilders (35 to 49)

2021 count

729

% of total

17.7%

Change from 2016

-0.8pp

Older workers and pre-retirees (50 to 59)

2021 count

494

% of total

12.0%

Change from 2016

0.0pp

Empty nesters and retirees (60 to 69)

2021 count

342

% of total

8.3%

Change from 2016

-0.5pp

Seniors (70 to 84)

2021 count

371

% of total

9.0%

Change from 2016

-0.3pp

Elderly aged (85 and over)

2021 count

139

% of total

3.4%

Change from 2016

+1.1pp

Data table

Service age groups for North St Marys. Age structure - Service age groups. 2021 and 2016 counts, percentages, and change compared with Penrith (C).

Service age groups for North St Marys. Age structure - Service age groups. 2021 and 2016 counts, percentages, and change compared with Penrith (C).
Service age groups for North St Marys. Age structure - Service age groups. 2021 and 2016 counts, percentages, and change compared with Penrith (C).
Category20212016Change
Count%Penrith (C)%Count%Penrith (C)%Countpp
Babies and pre-schoolers (0 to 4)2696.5%7.2%3087.9%7.4%-39-1.4pp
Primary schoolers (5 to 11)44010.7%9.9%43111.0%9.8%+9-0.3pp
Secondary schoolers (12 to 17)3448.3%7.8%2737.0%7.8%+71+1.3pp
Tertiary education and independence (18 to 24)3969.6%9.3%42810.9%9.9%-32-1.3pp
Young workforce (25 to 34)61414.9%15.2%52513.4%15.4%+89+1.5pp
Parents and homebuilders (35 to 49)72917.7%21.0%72518.5%20.5%+4-0.8pp
Older workers and pre-retirees (50 to 59)49412.0%11.4%47112.0%12.3%+230.0pp
Empty nesters and retirees (60 to 69)3428.3%9.5%3468.8%9.7%-4-0.5pp
Seniors (70 to 84)3719.0%7.5%3659.3%6.0%+6-0.3pp
Elderly aged (85 and over)1393.4%1.2%912.3%1.2%+48+1.1pp
Total4,123100.0%100.0%3,921100.0%100.0%+2020.0pp