In 2021, 96.7 per cent of Aboriginal and Torres Strait Islander children were enrolled in preschool programs for the year before school, the Productivity Commission confirmed in its Closing the Gap targets released on Thursday.

That's compared with 86.7 per cent for non-Indigenous children across the nation.

Data from the commission showed the Closing the Gap Target for Indigenous children in preschool was on track to be met by the 2025 deadline of more than 95 per cent.

Levels of preschool education among Indigenous children in the year before school have increased from 76.7 per cent in 2016.

Data for 2021 for three of the 17 outcomes of Closing the Gap were released on Thursday, ahead of the full annual report being handed down in July.

Other figures showed a decreasing rate of Indigenous people aged 10 to 17 years in detention in the past year.

During 2020/21, there were 23.2 per 10,000 Indigenous young people in detention, down from rates of 25.7 a year earlier, and 35 in 2010/11.

The current target is a 30 per cent reduction of Indigenous young people in detention by 2031.

While the commission said the target was on track to be met and showed good improvement, detention rates were above the rest of the population.

Detention rates for 2020/21 among non-Indigenous young people remained stable at 1.3 per 10,000 people.

The data also showed 34.3 per cent of Indigenous children were assessed as developmentally on track in all five areas of the Australian Early Development Census.

The proportion of children assessed as on track fell backwards in 2021 from the 35.2 per cent when the outcome was last measured in 2018.

Closing the Gap has aimed to have the figure reach as high as 55 per cent by 2031.

However, the current figures show the measure was behind the trajectory needed to reach the target.

July's data compilation report for the Closing the Gap targets will be the second time such figures would be compiled as a point-in-time snapshot of progress to meet the outcomes.

Australian Associated Press