If you look for statistics on how women have the upper-hand in term of choice of mate until some age in their thirties (varies by country/state) and the balance

If you look for statistics on how women have the upper-hand in term of choice of mate until some age in their thirties (varies by country/state) and the balance then brutally shifts the other way... then you will find plenty. sorry no time to look for references, but really this should be common knowledge