Taking into account that the estimated number of people on earth by the United States Census Bureau for 12/01/10 is 6,884,909,953.
I will assume half of those (3,442,454,976) are men.
The number of people one meet defining "meet" as "a face-to-face exchange containing a clear, if momentary, recognition" between oneself and another. Ranging from something as simple as a wave, a greeting or a smile all the way to a life long friendship (obviously everyone counts only once). Could be maybe (generously) like "William Least Heat Moon" said 100,000. Or it could be complete rubbish. But let's say it isn't (rubbish) and that half of those are men.
So
3,442,454,976 ---------- 100%
50,000 ------------------------ x%
x = percentage of men one could meet in 90 years of life = 0.001452%
Assuming she can only judge the assholeness of men she has actually met, and even if every men she met in her entire life was in fact an asshole. Only 0.001452 percent of all the men on the entire world would be an asshole. I like to think that is not much.
This number could be refined to less insulting numbers if we knew if she has traveled much within the country or world, how old is she, etc.