Earning a black belt in Jiu Jitsu, Kung Fu, Judo, Aikido and other martial arts?

[Drew]

I am doing a research project for school on earning black belts in different martial arts and fighting disciplines. I have found plenty of info on bjj, aikido, judo, tae kwan do. Now I know earning your black belt varies with time and the individual, but can anyone with experience approximate how long it took to earn a black belt/sash in Sil-Lum King Fu? Thanks for the help