Personally I don't use sleeping medicine, but my friend has used it and strongly recommends against it.
personally i dont know, but you are not suppossed to operate machinery or drive if you have taken any sleeping aids. also, you are taking this medications to help you fall asleep, so, should only be taken at bedtime, when you are about to sleep.
I would say very few probably 1%. These are the people who are taking it to try to get high on it. The people who are using it as a sleep aid, are NOT going to go out and try to operate a backhoe after taking one and going to bed. Plus the d#m things are expensive. Don't want to waste them when you could be using them for a good night sleep.