GP didn't specify, but IIRC vehicle incident rates are usually specified in terms of distance driven/ridden, so the stats they were looking at may have already taken that into account.

In my experience the number of female riders is so small, that from a statistical point of view it becomes almost irrelevant.

Women also tend to ride smaller bikes, for obvious reasons.

It was deaths/km ridden.

This would be better. Still does not take into account bigger and smaller bikes. I find it extremely difficult to judge that. From my experience, you are absolutely right. Men seem to take higher risk and some of them the consequences.

That’s the worst stat. By trip would be much better.

Motorcyclists on average ride less than 3,000 miles a year, cars are 4-6x that. 90% of accidents are within 10 miles of the riders home.