This graphic charting the variation of clitoral hoods was posted on a tumblr blog Uncutting - it was created by a 22 year-old guy who's currently restoring his foreskin and opposed to infant circumcision. He wondered whether clitoral hoods followed the same range in "coverage" as the Foreskin Coverage Index. They did.
I never thought of the clitoral hood as being the vulva equivalent of the foreskin. In our last bodysex workhsop during genital show & tell, one of the women had a very large and beautiful clitoral hood. It was the largest hood I've ever seen. I swear I could look at genitals all day.
Note that the fourth picture on the CI-1 level is of a woman who was the victim of FGM. They took her clitoral hood but left her clitoris and labia (thank god). Betty and I worked with a FGM survivor and they'd also cut her clitoral hood but left her clitoris intact. There are several types of FGM but we wonder how many women who think they've been mutilated actually have clitorises.
Thank you, Genevra, for the link.