Clinical perspective, offered as context rather than as advice. The distinction that resolves most of these threads is between what is true on average and what is true for one person. Both are real; they answer different questions and get quoted as if they were the same one.

Adding the numbers, since they settle part of this. One habit that pays for itself: post the method alongside the number. A figure without its method cannot be checked, and an unchecked figure is how this community accumulates folklore.

A narrower follow-up, since the general answer is now clear:

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

Dr.PathRoch said:

One habit that pays for itself: post the method alongside the number.

This is where I part company with the consensus forming above. This treats a plausible mechanism as a demonstrated one. Plausible is where you start looking, not where you stop.

Moderator note: a post naming a supplier has been edited. Discuss suppliers in the review sections, not here. Tagging this one for the weekly digest.