The statistics SBS quoted are as @raptortech97 cited from the Australian Bureau of Statistics, the official statistician of the Commonwealth of Australia.
To answer the other arm of your question, they are generally in line with statistics reported by other OECD countries.
The Centre for Disease Control puts the lifetime rate at 18.4% for US women:
Nearly 1 in 5 (18.3%) women and 1 in 71 men
(1.4%) reported experiencing rape at some time in
The UN Office on Drugs and Crime has for 2011 per annum (not lifetime) rates for "Sexual violence" here.
"Sexual violence" means rape and sexual assault; including sexual offences against children
Note the warning that cross-country comparisons are problematic:
Please note that when using the figures, any cross-national comparisons should be conducted with caution because of the differences that exist between the legal definitions of offences in countries, or the different methods of offence counting and recording.
It has Australia at 25 per 100,000 women per annum. Of the 29 OECD countries in the sample (Denmark, Korea and the United States are not included; Iceland and Turkey have no data for the relevant year and adopting a 2011 census figure of 62.3 million for UK population), Australia ranks 18th.
So, unfortunately the statistics are true.
Even more unfortunately, they are not particularly high by OECD comparisons.
It's hard to imagine that nearly 1 in 5 adult women have been sexually assaultedSimilar statistics are reported in the USA and in the UK.