[red-iron-pine]

Can't speak to age, but there is a well known phenomenon that fighter pilots only have girls.

What data there is backs that up, too.

https://www.upi.com/Archives/1987/12/01/Air-Force-fliers-rea...

Wouldn't surprise me if similar factors, e.g. stress on the body via aging, also impact the Y chrom and lead to more girls.