I am having a heckuva time convincing someone that the older a man is, the less likely he will find a mate wanting to start a family. (Particularly in the zone where the woman is still of childbearing age - and wanting to start a family - partnering up with an older man.) All I really need is a chart that shows frequency of first child as a function of paternal age. I don't want stats about how paternal age affects the outcome (health) - or how it affects fertility - those will skew the results of how many farther of what age are actually starting families. Cannot find such an animal. Very frustrating. I think it is actually too basic a statistic to generate any hits.