Perhaps it would be more useful to track how many grew up in biological, nuclear families. For instance, I know foster kids have high rates of crime, and I don't know where they'd be counted here. Black children are often raised by their grandparents and others. At this point, perhaps black great-grandparents are old enough to have come from a time when most people were married. There have been points in time where the black marriage rate was equal to (and I think even greater than) whites. The sharp divergence started around the same time as everything else went to shit, which is to say the 60s.