3 ms·
This paper says there are 200: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3275130/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3275130/ (well, it says "mor
by Johnny555 3y ago
This paper says there are 200:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3275130/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3275130/
(well, it says "more than 200" as of 2010, but that's unlikely to mean "north of a million" today)