If it were me, I'd set the fan to come on at 210 and go off at 200. Even at 200 your thermostat may not be completely open and people may say you should set it higher so that it's never on while the the thermostat is partially closed. However, my car starts running noticeably different around 220.
I'd like to talk a little more about that last sentence of mine. I've bought into the whole 195 degree thermostat thing experienced members espouse on here, however my personal experience is that I can tell when my car hits 220 that it's a little off. It starts missing at idle and just generally doesn't seem as smooth. Maybe that's due to the inadequacy of some other part when that part is hot, not sure, but 220 is not good for me even though 220 isn't out of the ordinary for a lot of others.