Colin is here for the badges, not reputation. And that's okay. Why rub it in by saying he's not even in top 99% of users?
It's like saying "he graduated in top 100% of his class".
I suggest not showing percentages above 50%.
As said in discussion that percentage is bit artificial at times.
How about just labeling the button "ranking" instead of "top % overall"? What do you need that percentage for?
Not showing percentage above 50% would create another problem. Users would be puzzled where the number has gone and how to get it back? That would lead to odd text in button which would try to explain missing percentage.