Deaths by horse-kick in Prussian Army cavalry corps
(Bortkiewicz 1898.) N is the number of units corresponding to
each number of deaths. No units had more than 5, so the counts are truncated
at 5 deaths.
"Bortkiewicz" <- data.frame(Deaths = c(0,1,2,3,4,5), N = c(109,65,22,3,1,0))