city-state luxuries

It's been fun going over polls for Returning Civs, Brand New Civs, etc. While I'm not overly familiar with the popular choices enough to confidently do a poll, I figured I'd start by finding out which city-states would be the most desired. I'd definitely recommend checking out the ultimate...

Hey all, I was wondering if anybody knew how Civ 5 assigns the luxuries that merc City States provide. Neither the XMLs for the CSs or the luxuries seem to suggest what belongs to who. At this point I am assuming that these are assigned randomly by the code. Please correct me if I am wrong...