My “SWAG” analysis is – this seems 2 to 3 times worse than the last bubble, which resulted in a trough-to-peak reduction in median price of about 10%. So, call it 25%.
Why median price? Because it is measureable. Why predict something you can’t measure, practically – like same house value.
Depending on the figure you use, 7 years of inflation could put this pretty close to 50%, inflation-adjusted, by the way.