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 medium-low income quartile held the largest share among residents aged 15 and over in Blewitt Springs, accounting for 29.7%.
Section overview
Individual income quartiles
Blewitt Springs - Persons aged 15+ (Usual residence)
This table summarises individual income quartiles for Blewitt Springs in 2021 for persons, with comparison against Onkaparinga (C) and change since 2016.
Individual income quartiles snapshot
2021 distribution by category for Blewitt Springs, with comparison markers for Onkaparinga (C).
Lowest group
2021 count
63
% of total
23.4%
Change from 2016
+20.3pp
63
23.4%
+20.3pp
Medium lowest
2021 count
80
% of total
29.7%
Change from 2016
-35.9pp
80
29.7%
-35.9pp
Medium highest
2021 count
68
% of total
25.3%
Change from 2016
+12.8pp
68
25.3%
+12.8pp
Highest group
2021 count
58
% of total
21.6%
Change from 2016
+2.8pp
58
21.6%
+2.8pp
Chart view
Individual income quartiles change
Absolute change in category counts between 2016 and 2021.
Lowest group
+62
+20.3pp
Medium lowest
+59
-35.9pp
Medium highest
+64
+12.8pp
Highest group
+52
+2.8pp
Data table
Individual income quartiles for Blewitt Springs. Individual income quartiles. 2021 and 2016 counts, percentages, and change compared with Onkaparinga (C).
| Category | 2021 | 2016 | Change | |||||
|---|---|---|---|---|---|---|---|---|
| Count | % | Onkaparinga (C)% | Count | % | Onkaparinga (C)% | Count | pp | |
| Lowest group | 63 | 23.4% | 24.7% | 1 | 3.1% | 23.5% | +62 | +20.3pp |
| Medium lowest | 80 | 29.7% | 30.5% | 21 | 65.6% | 29.9% | +59 | -35.9pp |
| Medium highest | 68 | 25.3% | 27.3% | 4 | 12.5% | 27.7% | +64 | +12.8pp |
| Highest group | 58 | 21.6% | 17.5% | 6 | 18.8% | 19.0% | +52 | +2.8pp |
| Total persons aged 15+ | 269 | 100.0% | 100.0% | 32 | 100.0% | 100.0% | +237 | 0.0pp |