When I was in the military, we had decades of compiled data to reflect this (from internal and external sources). I will look around the web (much like you can). I do not have access to this data anymore, but I saw the same type of data during my 15 years as a HR specialist. There have been several prominent women who have come out after finishing their terms as CEO, Governor ETC. who said things to the same effect. This is just my personal experience, but when we had new HR staff (new to HR and new to our company) they thought much the same as you. They were surprised to see the data and real world difference. The educational system, govt, and media have been conditioning us to ignore the differences between men and women for so long, many people can no longer see the obvious.

This is not popular, but I believe people should know when they are being brainwashed.