Because one million children were orphaned, child-headed households were a result of the genocide

I think your question is: after which Genocide was this the case?

It might have been more than one genocide, but it was definitely the case in the Rwandan Genocide. Specifically it is estimated that around 100 000 children live in such households. (but his data is from 2003, so in the meantime those children grew up)

Europeans are more concentrated in urban areas.