PedsEndoPhilly said:

The distinction that resolves most of these threads is between what is true on average and what is true for one person.

There is a second half to this that has not been said yet. If two explanations both fit, the useful question is which one predicts something the other does not. That is answerable; arguing about which sounds more plausible is not.

One concrete data point for the thread. For anyone reading later: the numbers in this thread are worth checking against a primary source before you act on them, including mine. Half the figures circulating in this community trace back to a secondary summary that dropped a qualifier.

One thing that is still open after PedsEndoPhilly’s answer:

Was that from a primary source or from a summary of one?

TirzTom said:

For anyone reading later: the numbers in this thread are worth checking against a primary source before you act on them, including mine.

I read this differently from TirzTom, on substance rather than tone. Not convinced. The evidence being cited is consistent with the conclusion and also consistent with two other conclusions nobody has ruled out.

Ask again with the specifics and you will get a better answer than this one.

TirzTom said:

For anyone reading later: the numbers in this thread are worth checking against a primary source before you act on them, including mine.

That is right for the common case. Whether it is right for the case being asked about depends on a detail that has not been given.