I am having a realllly tough time finding the most recent statistics - I will look further tomorrow. But, this is the best I could find from 2015 - 'hundreds' of children have been abused by foster carers (emotional, sexual, physical) from 40 000+ foster care placements in Australia. I will find something much more recent and share with you when I find it. The second article (below) is the process of removing a child in Australia into the care of foster parents (2019-2020). During 2018–19, 170,200 (30 per 1,000) Australian children received child protection services (investigation, care and protection order and/or were in out-of-home care). Aboriginal and Torres Strait Islander children were 8 times as likely as non-Indigenous children to have received child protection services. Children from geographically remote areas were more likely to be the subject of a substantiation, or be in out-of-home care than those from major cities. Over 3,700 children were reunified with family during 2018–19. I cannot see any statistics outlining abuse by foster carers for 2018-2019. I will keep searching
In 2019–20, about 174,700 children aged 0–17 received child protection services. These include investigations (which may or may not lead to substantiated cases of child abuse or neglect), care and protection orders and/or out-of-home care placements
. This equates to a rate of 31 per 1,000 children. More than half (57%) of these children were the subject of an investigation only and were not subsequently placed on a care and protection order or in out-of-home care. A small proportion (7.2%) were involved in all 3 components of the system. That is the third report below -
Hundreds of children in care abused last year, report finds
https://apo.org.au/sites/default/files/resource-files/2021-05/apo-nid312307.pdf
Child protection - Australian Institute of Health and Welfare