Population declining but prices are going up. How is that possible?

[Justin Brin]

According to the US census data Los Angeles, CA county population declined 3.5% in the last few years as you can see here:

(Data from April 2020 - July 2023).

But Real Estate prices went up in that period 25% according to Zillow (From $665,868 to $834,772).

Rents went up 18% (From $2,380 to $2,827).

How that can be?

If more people are leaving then coming in, prices should go down?

Unless there is a big increase in undocumented immigrants and then there is really an undocumented population increase and that's why prices are going up?

Can there be any other reason?