one area is the "point in time homeless surveys" here: https://hsh.sfgov.org/about/research-and-reports/san-francis... the data can be a little hard to interpret for different categories/parts of the report. For instance, when 10% of the respondents say they have been homeless for 30 days or less, you can extrapolate this and assume that this same number of people is rotating in and out of homelessness frequently and over a year the number of homeless in this bit is 12x the number in the point in time survey. I picked up a lot of this through volunteering and participating in homeless social services and doing housing related activism.