 Given differing populations over a long period of time, different policies at different times in different states (which also resulted in different definitions of target children), and incomplete records, accurate figures are difficult to establish.The academic Robert Manne has stated that the lower-end figure of one in 10 is more likely; he estimates that between 20,000 and 25,000 Aboriginal children were removed over six decades, based on a survey of self-identified Indigenous people by the television station ABS.According to the "Bringing Them Home" report