A yawning income and lifestyle gap has opened between the inner suburbs of Sydney and the rest of the city and the state.

Exclusive Bureau of Statistics analysis of census figures for The Sydney Morning Herald has revealed the median family income in inner Sydney – which includes suburbs within an arc stretching from the airport, northwest to Homebush, then northeast to Palm Beach – has reached $131,248 a year. That is $38,000 more than the rest of Sydney and almost $56,000 more than in regional NSW.

The bureau's special analysis underscores how inner Sydney has opted for a high-density lifestyle in unprecedented numbers. The 2016 census finds 49.2 per cent of the residents in that part of the city now live in a flat or apartment compared with 16.4 per cent in the rest of Sydney and just 6.44 per cent of those living outside of greater Sydney. Nationally, just over 13 per cent live in an apartment or flat.

Only one in three people in inner Sydney now live in a detached house while a further one in seven live in a "semi, terrace or townhouse".