What is the going Rate to charge for babysitting?

I currently work in a Latchkey setting and would like to make some extra money. I'm not a kid, and I have years of experience. I have college background in early childhood education also. What should I charge for babysitting? I know working as a full time nanny I was making $10 an hour but I don't think I can charge this much for babysitting on an as needed basis. What should I charge? I'm in Michigan.