Population Policy?
There is no limit they have put on population, only immigration. Australians and Immigrants both move overseas to live. They can be replaced with migrants. All other Australians can breed as much as they wish.
P.S. as with most years about 61,000 Australians bring in their Partners and kids to migrate to Australia and pay $6,865 for Partner and if applicable $1,720 kid under 18 for the privilege. + $418,765,000 per year. and $100,000 to bring in your parents.