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 Forestville (SA), accounting for 34.5%.
Section overview
Individual income quartiles
Forestville (SA) - Persons aged 15+ (Usual residence)
This table summarises individual income quartiles for Forestville (SA) in 2021 for persons, with comparison against Unley (C) and change since 2016.
Individual income quartiles snapshot
2021 distribution by category for Forestville (SA), with comparison markers for Unley (C).
Lowest group
2021 count
206
% of total
18.1%
Change from 2016
-3.6pp
206
18.1%
-3.6pp
Medium lowest
2021 count
265
% of total
23.3%
Change from 2016
+0.9pp
265
23.3%
+0.9pp
Medium highest
2021 count
274
% of total
24.1%
Change from 2016
+2.1pp
274
24.1%
+2.1pp
Highest group
2021 count
392
% of total
34.5%
Change from 2016
+0.6pp
392
34.5%
+0.6pp
Chart view
Individual income quartiles change
Absolute change in category counts between 2016 and 2021.
Lowest group
-29
-3.6pp
Medium lowest
+22
+0.9pp
Medium highest
+35
+2.1pp
Highest group
+25
+0.6pp
Data table
Individual income quartiles for Forestville (SA). 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 | 206 | 18.1% | 20.9% | 235 | 21.7% | 21.4% | -29 | -3.6pp |
| Medium lowest | 265 | 23.3% | 22.6% | 243 | 22.4% | 21.6% | +22 | +0.9pp |
| Medium highest | 274 | 24.1% | 22.3% | 239 | 22.0% | 21.8% | +35 | +2.1pp |
| Highest group | 392 | 34.5% | 34.2% | 367 | 33.9% | 35.2% | +25 | +0.6pp |
| Total persons aged 15+ | 1,137 | 100.0% | 100.0% | 1,084 | 100.0% | 100.0% | +53 | 0.0pp |