The ACT government has attributed the third consecutive year of falls in youth supervision rates to increased prevention and diversionary measures.

Eighty-nine young people, aged between 10 and 17, were under supervision on an average day in the ACT in 2013-14, down from 140 in the recent peak year of 2010-11.

The figures, released by the Australian Institute of Health and Welfare this week, showed a fall from the 111 average the year before, a drop of about 20 per cent.

Of the 89, 17 – about 19 per cent – were in detention, with the others under community-based orders. The data showed a continuing sharp fall in community supervision numbers was behind the overall drop, however The Sunday Canberra Times understands youth detention numbers have dropped well below 17 this financial year.

The decline in youth supervision numbers equated to a rate of 23 per 10,000 young people, the same as the national average. The ACT rate was 38 per 10,000 in 2010-11, and 28 in 2012-13. The national rate has fallen from 28 to 23 per 10,000 in five years.

Minister for Children and Young People Mick Gentleman said the government's 10-year blueprint for youth justice continued to be successful.

"Significant reductions in the numbers of young people under youth justice supervision in the ACT have been achieved by investing in prevention and diversionary initiatives that are working to divert young people away from, or reduce their involvement in the youth justice system," he said.

Mr Gentleman pointed to the achievements of the after-hours bail support service, which has operated since October 2011 to help young people on community-based orders meet their bail conditions.

"In 2013-14, the service successfully diverted 39 young people from custody at the Bimberi Youth Justice Centre," he said.

Continuity of case management and the use of restorative justice for Aborigines and Torres Strait Islanders and first-time offenders, where offenders hear directly from victims about harm caused, had also helped, the minister said.

Youth Coalition of the ACT director Emma Robertson said a "significant investment" in the culture and workforce at Bimberi, including the operation of the pre-release Bendora Transition Unit since 2011, together with the after-hours bail support service, had helped the fall in numbers.

"This area – youth justice – has been the big success story for the ACT government in making some significant inroads and changes," she said.

Indigenous young people were 12 times more likely than non-Indigenous youth to be under some form of supervision in the ACT, lower than the increasing national rate of 15 times more likely.