You're thinking of dividing by 0, if you divide 0 by any other number its 0 meaning your ka/d ratio in that situation is still 0. 1 kill and 0 deaths would be infinite kdr.
Nigerians are actually one of the most successful migrant groups in America.
Hispanics about to make the whole US brown, can’t have any more successful ethnic groups if you’re the only ethnic group. Well, it’s really a collection of ethnic groups, but only we Hispanics actually recognize that (at least inside the US).