It's its.

I saw this at the hospital this morning, since I don't recall ever being taught in my days at school the correct usage of it's or its I'd believe it'd be something rarely taught in Australia, even lovely Grace would tell of never knowing there was even a word its, she and it seems nearly all Aussies only know of it's, which isn't a possessive.
Literacy does appear to be waning in Australia despite massive increases in funding over recent years, there must be a huge black hole somewhere ensuring funding doesn't equal results.