I voted very few because most of the climbing I do is longer grades (over 1 mile). Being out of the saddle for those the whole time would suck the life out of me too early. On those climbs I do come out of the saddle periodically, but more for giving the "down there" region a little rest.

I do come up for some very short/steep rises if I want to keep my speed up or keep up with a group or something but I don't really consider those "climbs".