Earlier quoted context omitted.
75%?? source? That sounds like too much.
this source claims 72% is more accurate: https://www.quora.com/What-percentage-of-San-Francisco-apart...
I don't think most people enjoy this benefit of rent control, it wouldn't make sense to rent out properties. I wonder what is the effective rent control rate (that which has affected price significantly). Maybe a rental turnover rate would hint at a solution.