According to this article, 1 in 5 women have always been the dumper - and never the dumpee!
http://fivethirtyeight.com/datalab/are-women-more-likely-than-men-to-end-a-relationship/

I was usually the dumper, although I did get blindsided once and it was not fun. So I'm not in the 7% of men who have always been the dumper and never the dumpee.

ETA: Just added the poll from the article!