IMO, indigenous population growth was not linear nor is it...

IMO, indigenous population growth was not linear nor is it today.
The population impact of Aussie Ice Age of 20,000 years is not yet
understood.

https://www.australiangeographic.com.au/news/2013/09/ice-age-struck-indigenous-australians-hard/

And many of the 800,000 now who claim to be aborigine are not
fully aborigine. Hunter Gatherer populations have tended to
vary depending on the available food and the health threats such
as viruses etc. Just look at the devastating impact on indigenous populations
globally of diseases carried by colonisers ?

Agriculture gave global populations a dramatic lift together with migrations.

So "do the math" IMO is a bit more complex than any poster on these
threads is capable of at present given the lack of historical data.