APN Codex Node 21420 21400 — Demographic Analysis Certified

Ageing Population & Housing Needs

Z-Score
−0.1180σ
Period
Q1 2026
Position
75.9 of 175 qtrs
Vintage
2026-Q4
1Node Definition

Ageing Population & Housing Needs (21420) measures how fast the population is ageing: the change over the year in the old-age dependency ratio, the number of people aged 65 and over for every 100 people aged 15 to 64. Higher readings mean the population ageing faster, which shifts demand towards the kinds of housing older households need. It is a component of the APN Aggregate Demographic Index™ (21400), at a weight of 0.30.

Known limitations

Measure change, October 2026. Until October 2026 this node read the level of the dependency ratio, which rises almost in a straight line (a correlation with time of 0.99 over 2011–2025), so its position measured the date rather than conditions. The node now reads the rate of ageing, and the level is shown as context. Because the ratio divides older residents by working-age residents, migration, which is mostly of working age, slows the reading when it rises and speeds it up when it falls.

2Metric Definition

Primary metric: Node Z-Score (Z21420)

Z-Score Construction
Current (Q1 2026)−0.1180σ
RtOld-age dependency ratio, end of quarter t: 27.24 people aged 65+ per 100 aged 15–64 at March 2026, 26.81 a year earlier
ΔRtChange over four quarters: +0.43 per 100 in the year to March 2026
μ, σBaseline mean and sample standard deviation of the change, 2011–2025 (+0.45 and 0.20, 60 quarters)

Metric typology: single-series Z-score of a four-quarter change in a ratio.

3Data Sources
InputSourceFrequencyCoverage
Estimated resident population by single year of age, AustraliaABS National, state and territory population (3101.0), through the ABS Data API (ERP_Q)QuarterlySeptember quarter 1981 to March quarter 2026

Tier-1 sovereign statistical releases (ABS). No commercial data provider dependency exists within this node.

4Reading History

The chart shows the node’s reading in every quarter, measured against the 2011–2025 baseline.

Ageing Population & Housing Needs (21420) · Reading History
Node Z-Score by Quarter, March 2011 to March 2026
−0.1180σ · position 75.9, ranked against 175 quarters
Reading, ranked quartersNormal range (middle 80% of ranked quarters)Current reading

The March quarter 2026 reading, −0.1180σ, ranks 75.9 against 175 quarters and sits inside the normal range of −1.7272σ to +0.1805σ. The highest ranked reading was +2.3096σ in the March quarter 2021, and the lowest −2.3932σ in the June quarter 2023.

Show the data
QuarterReadingBasis
Q3 1982−1.6853σRanked
Q4 1982−1.7267σRanked
Q1 1983−1.7292σRanked
Q2 1983−1.6732σRanked
Q3 1983−1.5429σRanked
Q4 1983−1.5211σRanked
Q1 1984−1.5395σRanked
Q2 1984−1.6190σRanked
Q3 1984−1.4971σRanked
Q4 1984−1.4215σRanked
Q1 1985−1.3437σRanked
Q2 1985−1.2637σRanked
Q3 1985−1.2520σRanked
Q4 1985−1.1110σRanked
Q1 1986−0.9707σRanked
Q2 1986−0.8165σRanked
Q3 1986−0.7627σRanked
Q4 1986−0.8987σRanked
Q1 1987−1.0010σRanked
Q2 1987−1.0896σRanked
Q3 1987−1.1559σRanked
Q4 1987−1.2130σRanked
Q1 1988−1.3555σRanked
Q2 1988−1.3912σRanked
Q3 1988−1.4559σRanked
Q4 1988−1.3908σRanked
Q1 1989−1.3013σRanked
Q2 1989−1.2653σRanked
Q3 1989−1.3457σRanked
Q4 1989−1.4234σRanked
Q1 1990−1.4520σRanked
Q2 1990−1.4603σRanked
Q3 1990−1.1629σRanked
Q4 1990−0.9378σRanked
Q1 1991−0.8185σRanked
Q2 1991−0.7235σRanked
Q3 1991−0.8012σRanked
Q4 1991−0.8244σRanked
Q1 1992−0.8265σRanked
Q2 1992−0.9122σRanked
Q3 1992−0.9072σRanked
Q4 1992−0.8962σRanked
Q1 1993−0.8511σRanked
Q2 1993−0.7403σRanked
Q3 1993−0.7700σRanked
Q4 1993−0.8347σRanked
Q1 1994−0.9204σRanked
Q2 1994−1.0408σRanked
Q3 1994−1.2391σRanked
Q4 1994−1.2796σRanked
Q1 1995−1.3158σRanked
Q2 1995−1.4204σRanked
Q3 1995−1.3229σRanked
Q4 1995−1.4201σRanked
Q1 1996−1.4103σRanked
Q2 1996−1.3662σRanked
Q3 1996−1.4907σRanked
Q4 1996−1.4620σRanked
Q1 1997−1.5081σRanked
Q2 1997−1.4678σRanked
Q3 1997−1.4741σRanked
Q4 1997−1.4840σRanked
Q1 1998−1.5373σRanked
Q2 1998−1.5829σRanked
Q3 1998−1.5476σRanked
Q4 1998−1.5757σRanked
Q1 1999−1.5902σRanked
Q2 1999−1.6287σRanked
Q3 1999−1.6392σRanked
Q4 1999−1.7071σRanked
Q1 2000−1.7366σRanked
Q2 2000−1.7546σRanked
Q3 2000−1.6638σRanked
Q4 2000−1.5335σRanked
Q1 2001−1.5068σRanked
Q2 2001−1.3941σRanked
Q3 2001−1.4449σRanked
Q4 2001−1.6033σRanked
Q1 2002−1.5295σRanked
Q2 2002−1.6973σRanked
Q3 2002−1.7978σRanked
Q4 2002−1.7699σRanked
Q1 2003−1.8220σRanked
Q2 2003−1.7850σRanked
Q3 2003−1.7152σRanked
Q4 2003−1.6533σRanked
Q1 2004−1.6652σRanked
Q2 2004−1.6218σRanked
Q3 2004−1.5751σRanked
Q4 2004−1.5747σRanked
Q1 2005−1.5848σRanked
Q2 2005−1.5908σRanked
Q3 2005−1.6099σRanked
Q4 2005−1.6547σRanked
Q1 2006−1.7276σRanked
Q2 2006−1.7861σRanked
Q3 2006−1.6708σRanked
Q4 2006−1.5927σRanked
Q1 2007−1.5365σRanked
Q2 2007−1.4676σRanked
Q3 2007−1.5965σRanked
Q4 2007−1.6914σRanked
Q1 2008−1.7999σRanked
Q2 2008−1.9042σRanked
Q3 2008−1.8601σRanked
Q4 2008−1.7464σRanked
Q1 2009−1.6013σRanked
Q2 2009−1.3509σRanked
Q3 2009−1.0782σRanked
Q4 2009−0.8424σRanked
Q1 2010−0.5611σRanked
Q2 2010−0.3806σRanked
Q3 2010−0.1722σRanked
Q4 2010−0.0845σRanked
Q1 2011−0.0520σRanked
Q2 2011−0.0486σRanked
Q3 2011+0.0827σRanked
Q4 2011+0.2171σRanked
Q1 2012+0.3583σRanked
Q2 2012+0.5397σRanked
Q3 2012+0.2920σRanked
Q4 2012+0.2362σRanked
Q1 2013+0.1613σRanked
Q2 2013+0.1134σRanked
Q3 2013+0.1988σRanked
Q4 2013+0.1933σRanked
Q1 2014+0.1519σRanked
Q2 2014+0.1125σRanked
Q3 2014+0.0781σRanked
Q4 2014+0.1156σRanked
Q1 2015+0.1090σRanked
Q2 2015+0.1125σRanked
Q3 2015+0.1223σRanked
Q4 2015+0.1250σRanked
Q1 2016+0.1146σRanked
Q2 2016+0.1317σRanked
Q3 2016+0.0367σRanked
Q4 2016−0.0682σRanked
Q1 2017−0.2063σRanked
Q2 2017−0.2625σRanked
Q3 2017−0.3279σRanked
Q4 2017−0.1943σRanked
Q1 2018−0.0970σRanked
Q2 2018−0.0415σRanked
Q3 2018+0.0492σRanked
Q4 2018+0.0165σRanked
Q1 2019−0.0247σRanked
Q2 2019+0.0571σRanked
Q3 2019+0.2580σRanked
Q4 2019+0.6846σRanked
Q1 2020+1.0708σRanked
Q2 2020+1.3864σRanked
Q3 2020+2.0209σRanked
Q4 2020+2.0823σRanked
Q1 2021+2.3096σRanked
Q2 2021+2.1501σRanked
Q3 2021+1.8054σRanked
Q4 2021+1.2682σRanked
Q1 2022+0.3549σRanked
Q2 2022−0.2587σRanked
Q3 2022−1.2656σRanked
Q4 2022−1.8241σRanked
Q1 2023−2.1574σRanked
Q2 2023−2.3932σRanked
Q3 2023−2.3366σRanked
Q4 2023−2.0578σRanked
Q1 2024−1.7168σRanked
Q2 2024−1.2265σRanked
Q3 2024−0.8089σRanked
Q4 2024−0.5677σRanked
Q1 2025−0.3961σRanked
Q2 2025−0.2941σRanked
Q3 2025−0.2953σRanked
Q4 2025−0.1948σRanked
Q1 2026−0.1180σRanked
Z-Score
−0.1180σ
Q1 2026
Position
75.9
ranked against 175 quarters
Change over the year
+0.43 per 100
to March 2026
Dependency ratio
27.24
per 100 aged 15–64, context
Fastest ageing
+0.92
March 2021
Slowest ageing
−0.03
June 2023
5Analytical Interpretation

At −0.1180σ (Q1 2026), the population aged at about its usual pace: the dependency ratio rose 0.43 per 100 in the year to March 2026, to 27.24, against a 2011–2025 average rise of 0.45. Position. 75.9, ranked against 175 quarters since September 1982: ageing in the 2010s and 2020s is faster than in the 1980s and 1990s, so an average recent reading ranks high in the longer record.

Ageing was fastest in the year to March 2021 (+0.92), while the border was closed and few working-age migrants arrived, and briefly reversed in the year to June 2023 (−0.03), when migration surged. It has returned towards its usual pace since.

7Certification Statement
APN Codex Node 21420 — Ageing Population & Housing Needs — Certified
  • The input is a Tier-1 sovereign statistical release (ABS)
  • The Z-score of −0.1180σ (Q1 2026) is derived directly from the input against the 2011–2025 baseline, not manually entered or estimated
  • The position is an empirical percentile rank against 175 quarters
  • The change from the level to the rate of ageing, and the effect of migration on the ratio, are disclosed