New South Wales has maintained its spot as Australia's top-performing state economy, while the Northern Territory is growing faster than anywhere else, according to CommSec's latest snapshot of the Australian economy.

Key points: NSW economy led by housing construction and business spending

NSW economy led by housing construction and business spending NT economy boosted by gas project, low unemployment

NT economy boosted by gas project, low unemployment WA continues to lag other states as mining investment boom falls

The quarterly State of the States report uses eight key economic indicators to compare each state against its own average performance over the past decade.

CommSec economist Savanth Sebastian said the states and territories can be grouped into three, thanks to Western Australia dropping back to become the worst performing economy.

"You've got NSW, Victoria and the ACT certainly leading the charge and in the front," he observed.

"Then you've got not much separating South Australia, the Northern Territory, Queensland and Tasmania, and then Western Australia seems to lag behind."

Mr Sebastian said New South Wales had been helped by the construction boom over the last quarter, with top rankings for business investment, retail trade and dwelling starts.

"It's pretty clear that New South Wales held firmly onto the top spot as the best performing economy," Mr Sebastian concluded.

Housing starts in New South Wales were a staggering 76 per cent above decade averages for the June quarter, while starts were also 13.3 per cent higher than a year ago for the June quarter.

Business spending in the state was 17.6 per cent above the average for the decade.

NT economy growing fastest ... for now

Meanwhile the Northern Territory economy has relied on its own large-scale engineering and construction projects to top the charts on economic growth, with nominal activity 24.1 per cent above the decade average.

It has also seen the lowest level of joblessness in the country, at 14.6 per cent below its decade average.

The report also found construction work there was 30.6 per cent above its decade average, thanks to gas projects.

But this figure was down almost a third on a year ago, showing that economic momentum is slowing.

The report showed new business investment in the Territory dropped 43 per cent over the same period.

"With the gas projects coming to completion, unless there's another kick, in terms of activity the Northern Territory does have some issues over the next 12 to 18 months," Mr Sebastian warned.

Coal boosts Queensland, Victorian population jumps

The report found the Queensland economy, ranked sixth for the last quarter, also has scope to improve, supported by housing construction, tourism, and agricultural exports.

Housing starts were 34.2 per cent above decade averages for the Queensland, while stronger prices for coal are also encouraging for the state's economy, the report found.

Victoria is now top ranked on population growth for the June quarter, and near the top of the chart on retail trade and business investment.

The state has seen its economy grow by 6.4 per cent in trend terms on a year ago, with retail spending 14.2 per cent above decade average levels, and housing starts 30.9 per cent above average for that period.

However, Victoria's Treasurer Tim Pallas acknowledged his state's rate of population growth is a double-edged sword.

"With that comes the need to continue to improve the facilities the state offers and, therefore, preserve our amenities and that's why the state is investing so substantially to grow our infrastructure so that the community can have the facilities that they need and deserve," he said.