The publication Youth detention population in Australia 2016 can be found on the AIHW Website.
The report presents information on the youth detention population in Australia, focusing on quarterly trends from June 2012 to June 2016. On an average night in the June quarter 2016, there were just over 900 young people in detention, over half of whom were unsentenced. Numbers and rates of young people in detention dropped slightly over the four years; however, this trend varied between different states and territories. Around half of all young people in detention on an average night were Indigenous.
The data set provided on data.gov.au contains data on young people in detention from June 2008 to June 2016. Some data may differ to the results published in Youth detention population in Australia 2016 due to data revisions.