The following screenshot explains it all:


(http://osu-ppy-sh.tvgratuite.org/p/pp?c=KH)

There aren't 38 players in this country but only 10. Or maybe there are 38 players but 28 hidden?
This bug affects every country (see Bahrein...)

a peppy <-- lol

they don't have pp so they just don't be displayed (can't rank)

I can see this as well, confirmed.

but low priority.

Players that have 0pp will not be listed.

If you go to the old Ranked-score based Country ranking for Cambodia, you can see all the remaining players (though players might not be listed on the old ranking when they never play specific modes).