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 highest income quartile held the largest share among residents aged 15 and over in Williams (S), accounting for 30.8%.
Section overview
Individual income quartiles
Williams (S) - Persons aged 15+ (Usual residence)
This table summarises individual income quartiles for Williams (S) in 2021 for persons, with comparison against Regional WA and change since 2016.
Individual income quartiles snapshot
2021 distribution by category for Williams (S), with comparison markers for Regional WA.
Lowest group
2021 count
111
% of total
16.0%
Change from 2016
-0.6pp
111
16.0%
-0.6pp
Medium lowest
2021 count
161
% of total
23.3%
Change from 2016
+0.3pp
161
23.3%
+0.3pp
Medium highest
2021 count
207
% of total
29.9%
Change from 2016
-0.1pp
207
29.9%
-0.1pp
Highest group
2021 count
213
% of total
30.8%
Change from 2016
+0.4pp
213
30.8%
+0.4pp
Chart view
Individual income quartiles change
Absolute change in category counts between 2016 and 2021.
Lowest group
-4
-0.6pp
Medium lowest
+2
+0.3pp
Medium highest
0
-0.1pp
Highest group
+3
+0.4pp
Data table
Individual income quartiles for Williams (S). Individual income quartiles. 2021 and 2016 counts, percentages, and change compared with Regional WA.
| Category | 2021 | 2016 | Change | |||||
|---|---|---|---|---|---|---|---|---|
| Count | % | Regional WA% | Count | % | Regional WA% | Count | pp | |
| Lowest group | 111 | 16.0% | 24.1% | 115 | 16.6% | 22.1% | -4 | -0.6pp |
| Medium lowest | 161 | 23.3% | 25.7% | 159 | 23.0% | 24.3% | +2 | +0.3pp |
| Medium highest | 207 | 29.9% | 23.0% | 207 | 30.0% | 22.8% | 0 | -0.1pp |
| Highest group | 213 | 30.8% | 27.3% | 210 | 30.4% | 30.7% | +3 | +0.4pp |
| Total persons aged 15+ | 692 | 100.0% | 100.0% | 691 | 100.0% | 100.0% | +1 | 0.0pp |