Number of Members on a particular day (historical data)

Hello,

I'm looking for help with finding how many Members our Foundation had on any given date. Does anyone have a custom report like this or any insight on how to pull this information? I've tried with the canned reports and with T-stats; with T-stats I've been able to find how many new members may have signed up for a given date, however I'm trying to find our all-in number on any given past date. Any suggestions are appreciated!