Income
Individual income quartiles
About this topic
Individual income quartiles group people aged 15 years and over into four evenly sized income ranges so the distribution of personal income can be compared objectively across areas and over time. The quartile method focuses on relative position in the income distribution rather than raw dollar brackets.
This topic is useful because direct income amounts are affected by inflation and wider economic change. Quartiles provide a clearer way to compare whether an area is becoming relatively lower, middle, or higher income over time.
Interpretation notes
- This is a derived distribution of personal income for people aged 15 years and over, with each quartile representing a quarter of the income distribution.
- Quartiles show relative position rather than fixed dollar brackets, which makes them more robust for comparisons over time.
Key insight
In 2021, the lowest income quartile held the largest share among residents aged 15 and over in Koondoola, accounting for 36.9%.
Section overview
Individual income quartiles
Koondoola - Persons aged 15+ (Usual residence)
This table summarises individual income quartiles for Koondoola in 2021 for persons, with comparison against Wanneroo (C) and change since 2016.
Individual income quartiles snapshot
2021 distribution by category for Koondoola, with comparison markers for Wanneroo (C).
Lowest group
2021 count
1,063
% of total
36.9%
Change from 2016
+18.7pp
1,063
36.9%
+18.7pp
Medium lowest
2021 count
873
% of total
30.3%
Change from 2016
+2.6pp
873
30.3%
+2.6pp
Medium highest
2021 count
700
% of total
24.3%
Change from 2016
+2.3pp
700
24.3%
+2.3pp
Highest group
2021 count
243
% of total
8.4%
Change from 2016
-23.7pp
243
8.4%
-23.7pp
Chart view
Individual income quartiles change
Absolute change in category counts between 2016 and 2021.
Lowest group
+1,034
+18.7pp
Medium lowest
+829
+2.6pp
Medium highest
+665
+2.3pp
Highest group
+192
-23.7pp
Data table
Individual income quartiles for Koondoola. Individual income quartiles. 2021 and 2016 counts, percentages, and change compared with Wanneroo (C).
| Category | 2021 | 2016 | Change | |||||
|---|---|---|---|---|---|---|---|---|
| Count | % | Wanneroo (C)% | Count | % | Wanneroo (C)% | Count | pp | |
| Lowest group | 1,063 | 36.9% | 25.7% | 29 | 18.2% | 25.5% | +1,034 | +18.7pp |
| Medium lowest | 873 | 30.3% | 23.7% | 44 | 27.7% | 21.3% | +829 | +2.6pp |
| Medium highest | 700 | 24.3% | 25.6% | 35 | 22.0% | 24.7% | +665 | +2.3pp |
| Highest group | 243 | 8.4% | 25.0% | 51 | 32.1% | 28.5% | +192 | -23.7pp |
| Total persons aged 15+ | 2,879 | 100.0% | 100.0% | 159 | 100.0% | 100.0% | +2,720 | 0.0pp |