Heh, well, my method of determining that isn't very efficient. I went to the moderator log and sorted by rubah and then scrolled down and manually counted how many times she closed a thread. Took about five minutes. I think it would take forever to do that for everyone. BoB probably has a really efficient way of doing that.
EDIT: It also appears that the log only goes back to April 2004, which for rubah is fine but for a lot of us it would be wildly innacurate.