I'm not sure where to find the numbers but the experts usually have some sort of 'formula/guess' and so they can usually get a pretty good idea of how many people probably have it.
As far as I can ever recall they are usually about right though I think they overestimated some like MERS and maybe SARS too but the point is that they have some good idea.
Nobody is saying we DO KNOW like objectively as if we have GPS on Corona 'Hosts' bodies but yes there is 'know' as in they have very good reasons, tried and tested, to know something that is probably about correct in any meaningful ways.
I'm not sure where to find the numbers but the experts usually have some sort of 'formula/guess' and so they can usually get a pretty good idea of how many people probably have it.
As far as I can ever recall they are usually about right though I think they overestimated some like MERS and maybe SARS too but the point is that they have some good idea.
Nobody is saying we DO KNOW like objectively as if we have GPS on Corona 'Hosts' bodies but yes there is 'know' as in they have very good reasons, tried and tested, to know something that is probably about correct in any meaningful ways.