YES! This is not a custom connected to Islam. It's an ethnic/cultural/geographical thing. In countries where it's prevalent, it's practiced by Christians, Muslims, African tribal religions, etc. Ethiopia is only about half Muslim, with most of the rest of the population being Christian, and the mutilation rate there is 90%.
Sorry, but according to a Malawi stats site,
Female Genital Mutilation (FGM): A few small ethnic groups practice female genital mutilation About 18% of females undergo this practice.
That's a far cry from 90% and it's still an accusation unless you can prove it.