I was somewhat surprised by that, I've just been googling a lot of authors to check (and dual nationalities are being included). I've also read a lot more Nigerian authors than I realised (many of whom are SFF authors), and more Polish authors too.

197 countries = the 193 UN recognised countries + Palestine, the Vatican, Taiwan and Kosovo as a fairly well accepted list. The Vatican is going to be difficult (impossible?) unless I include nonfiction but that may be necessary anyway. So far I've counted fiction & poetry.