Did most former presidents keep their civilian homes before they moved to the White House, or did most sell them?

This came out of a discussion regarding the extreme security measures that NYC is being forced to pay in order to secure a full time resident, Melania and Barron, and, to a lesser extent (I hope) trump.
It came to my attention that the Obama’s kept their former house, and visited a handful of times. Security needed to be provided 24/7 for that home, but the vast majority of the time it was just a couple of SUVs parked at either end of the block.

So, have most presidents kept their old homes, or sold them? And what did it cost for security on them?