I do not know what the comparable statistic is for Australia, but my best guess is that it is not too far behind the US, where one in five of Generation Z now identify as LGBTQ. The American Conservative.com has an article thinking through the logical, or rather demographic consequences of this, as the numbers seem to expand all the time, going up with each survey. This socially learned set of behaviours will rapidly reduce population numbers, which are precarious even now. From a biological perspective, this is but one more depopulation factor. The Left, no doubt, will see this as a good thing.
https://www.theamericanconservative.com/articles/the-lgbtsqewing-of-america/