New arrivals are powering the state’s population growth with overseas migration accounting for 80 per cent of the increase in the NSW population last year.

Net overseas migration to the state was a record 98,800 in the 12 months to September 2017, up 17 per cent on the previous year. The majority of overseas arrivals to NSW typically settle in Sydney.

The annual increase in overseas migrants to NSW was 4400 more than the number of new births in the state, meaning migration contributed more to population growth than newborns in the year to September.

The new population statistics released by the Bureau of Statistics on Thursday come amid national debate over population levels and as governments struggle to relieve pressure on overstretched transport infrastructure and social services.

The figures revealed the number of births per woman in NSW slumped to 1.645 last financial year, the lowest in Australia, raising the prospect that soaring house prices in Sydney are taking a toll on the fertility rate.