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 Millswood, accounting for 41.2%.
Section overview
Individual income quartiles
Millswood - Persons aged 15+ (Usual residence)
This table summarises individual income quartiles for Millswood in 2021 for persons, with comparison against Unley (C) and change since 2016.
Individual income quartiles snapshot
2021 distribution by category for Millswood, with comparison markers for Unley (C).
Lowest group
2021 count
376
% of total
21.3%
Change from 2016
+0.6pp
376
21.3%
+0.6pp
Medium lowest
2021 count
295
% of total
16.7%
Change from 2016
-25.7pp
295
16.7%
-25.7pp
Medium highest
2021 count
369
% of total
20.9%
Change from 2016
-2.4pp
369
20.9%
-2.4pp
Highest group
2021 count
728
% of total
41.2%
Change from 2016
+27.5pp
728
41.2%
+27.5pp
Chart view
Individual income quartiles change
Absolute change in category counts between 2016 and 2021.
Lowest group
+211
+0.6pp
Medium lowest
-43
-25.7pp
Medium highest
+183
-2.4pp
Highest group
+619
+27.5pp
Data table
Individual income quartiles for Millswood. Individual income quartiles. 2021 and 2016 counts, percentages, and change compared with Unley (C).
| Category | 2021 | 2016 | Change | |||||
|---|---|---|---|---|---|---|---|---|
| Count | % | Unley (C)% | Count | % | Unley (C)% | Count | pp | |
| Lowest group | 376 | 21.3% | 20.9% | 165 | 20.7% | 21.4% | +211 | +0.6pp |
| Medium lowest | 295 | 16.7% | 22.6% | 338 | 42.4% | 21.6% | -43 | -25.7pp |
| Medium highest | 369 | 20.9% | 22.3% | 186 | 23.3% | 21.8% | +183 | -2.4pp |
| Highest group | 728 | 41.2% | 34.2% | 109 | 13.7% | 35.2% | +619 | +27.5pp |
| Total persons aged 15+ | 1,768 | 100.0% | 100.0% | 798 | 100.0% | 100.0% | +970 | 0.0pp |