Should Twitterati Top 100 List be 50% Women?

This is a list that Foreign Policy compiled of the top 100 Twitter Feeds - the so called Twitterati.

On counting about 15 - from what I could gather in recognising names - are female.

Shouldn't there be more than that? Are there really only 15 influential women we want to hear from and the rest are men? Or is it that it's a representation of how little of the world's establishment women have a share of?