Here's the source for Japan: http://www.maff.go.jp/j/chikusan/sinko/l...orse_1.pdf
You propably don't speek Japanese either, but according to this: https://www.quora.com/How-many-horses-ar...e-in-Japan
it's 83,129 horses in 2008.
Here's a list of various countries: Note that there are almost no south asian, sub saharan african and middle eastern countries in the top ones, so a large majority of people on earth have no access to horses.
https://www.horsetalk.co.nz/2017/07/10/w...0-million/