Glad to hear that. That term "black on black" whether in reference to crime in general or homicide in particular really really burns my ass. I mean, Chinese people in China tend to kill other Chinese people? Shock! Surprise! Who'da thunk it!
So yeah.
EDIT: I have answered @cupidzero.
Yeah I was under the impression (perhaps wrongly so - will wait for the edit to your post you offered to @cupidzero) that black on black killings were higher per population percentage too. If that graph you provided is indeed accurate then that wouldn't seem to be the case.