I also think the numbers are a bit skewed because although someone may end up on the ground, does not mean that the fight is taken there. For instance, if a fight ends in a ko, obviously the fighter who was ko'ed ends up on the ground. Most instances a ko means the end of the fight. (MOST not all, of course there are exceptions and Im talking mostly in terms of a street fight)

Did the find end up on the ground? Yes. Does that make it a ground fight? No.

I can't count how many times someone was knocked down in a fight and was got back up before the other person was able to capitalize. Did the fight go to the ground in those instances, yes. Was it a ground fight? No.