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-high income quartile held the largest share among residents aged 15 and over in Blacktown, accounting for 29.5%.
Section overview
Individual income quartiles
Blacktown - Persons aged 15+ (Usual residence)
This table summarises individual income quartiles for Blacktown in 2021 for persons, with comparison against Blacktown (C) and change since 2016.
Individual income quartiles snapshot
2021 distribution by category for Blacktown, with comparison markers for Blacktown (C).
Lowest group
2021 count
10,127
% of total
26.8%
Change from 2016
+3.9pp
10,127
26.8%
+3.9pp
Medium lowest
2021 count
9,665
% of total
25.6%
Change from 2016
-10.8pp
9,665
25.6%
-10.8pp
Medium highest
2021 count
11,138
% of total
29.5%
Change from 2016
+6.4pp
11,138
29.5%
+6.4pp
Highest group
2021 count
6,788
% of total
18.0%
Change from 2016
+0.3pp
6,788
18.0%
+0.3pp
Chart view
Individual income quartiles change
Absolute change in category counts between 2016 and 2021.
Lowest group
+9,792
+3.9pp
Medium lowest
+9,131
-10.8pp
Medium highest
+10,800
+6.4pp
Highest group
+6,529
+0.3pp
Data table
Individual income quartiles for Blacktown. Individual income quartiles. 2021 and 2016 counts, percentages, and change compared with Blacktown (C).
| Category | 2021 | 2016 | Change | |||||
|---|---|---|---|---|---|---|---|---|
| Count | % | Blacktown (C)% | Count | % | Blacktown (C)% | Count | pp | |
| Lowest group | 10,127 | 26.8% | 26.4% | 335 | 22.9% | 26.4% | +9,792 | +3.9pp |
| Medium lowest | 9,665 | 25.6% | 22.3% | 534 | 36.4% | 22.1% | +9,131 | -10.8pp |
| Medium highest | 11,138 | 29.5% | 27.2% | 338 | 23.1% | 27.4% | +10,800 | +6.4pp |
| Highest group | 6,788 | 18.0% | 24.1% | 259 | 17.7% | 24.1% | +6,529 | +0.3pp |
| Total persons aged 15+ | 37,718 | 100.0% | 100.0% | 1,466 | 100.0% | 100.0% | +36,252 | 0.0pp |