Figures from the Australian Bureau of Statistics showed the population of NSW increased by 6.8 per cent.

The Regional Population Growth, Australia, 2012 report showed population growth was most prominent in outer suburbs, inner cities, urban infill areas, along the coast and mining areas.

Areas that saw decline included well-established suburbs in capital cities and inland rural areas.

Many western NSW towns experienced population losses in the reporting period.

These included Brewarrina (4.5 per cent), Cobar (2.8 per cent), Walgett (2.6 per cent) Bourke (1.5 per cent), Warrumbungle and Gilgandra (1.2 per cent) and Coonamble (0.4 per cent).

A statistical area that combined Bourke, Cobar and Coonamble had the ninth-fastest decline of any region in Australia (1.4 per cent).

Some western towns, however, bucked that trend.

Wellington, which played host to the opening of a 600-bed correctional centre in 2007, recorded a 6.1 per cent increase in its population.

Warren experienced a 4.1 per cent increase and Narromine a 2.6 per cent increase.

Population growth in Greater Sydney accounted for 74 per cent of the state's total growth in the five years to June 2012.

NSW LGAs with some of the largest percentage population increases included Canada Bay (17.1), Camden (16.0), Yass Valley (14.8), Auburn (14.5), Parramatta (13.7) and Palerang (13.5).

Australia's so-called centre of population, the point marking the average latitude and longitude around which the population is distributed, is in fact located in western NSW.

At June 30, 2012, it was 34 kilometres east of Ivanhoe, a figure the ABS says reflects he concentration of population in south-east Australia.

The centre of population moved 17 kilometres north west between 2007 and 2012, showing rapid population growth in Queensland and Western Australia over the period.