I think blacks make up more then 13% of the US population, that's why some of the stats doesn't add up right, when considering the number of AIDS cases, folks in jail, on welfare, etc.
Mixed blacks who could pass for white, some of them would pass for Jewish, and this has been done since slavery, as even WEB Debuis (founder of the NAACP) was educated in Berlin, and this was in the 1800s. Funny how the Jews are supports of Blacks, but I suspect it happened via mixed blacks who passed as "jewish" looking, and also, in the black occult or mason, if you look Jewish then you are "in", thus, blacks who looked white worked from within.
Blacks wouldn't be as open to IR mating if their children always turned out white. The only reason they are OK with it is because they know the child will be black, and usually for about 3 generations. That's why the South had a 1/4 rule, in being "white", you had to have white heritage for 4 generations to be totally "white", meaning that the black frizzy hair, dark skin, and broad nose will not pop out all of the sudden anymore. But again, that takes about 4 generations for it to happen. So, blacks are ok with mixing for this reason,imo.