It didn’t say “The Commonwealth it Australia’s existence” it said 57% of Australia’s history which I maintain is fundamentally incorrect.
However, I think there is nothing further to be gained here as we would be arguing semantics.
However, I think there is nothing further to be gained here as we would be arguing semantics.
It's common for "Australia's history" to refer to pre-colonisation in addition to the last couple of hundred years.
This is almost certainly because Australians see the country and the continent as 'the same' for all intents and purposes.