How often do we wash our hands?

Last weekend we decorated my hand and my wife’s belly with some henna. In less than a week mine was gone and her’s was just starting to fade in a few places. That got me wondering: how many times do I wash my hands in an average day… So today I’m counting hand washes. It’s 11AM and I’m up to 8 already. (I think her belly washes have remained at 1.)