Does your cat shed hair excessively?

My Persian shed constantly. There was always long, white cat hair all over the place. We had to brush him frequently. My current tabby sheds a lot during the summer, but it obviously isn't as noticeable. When she sits on your lap and gets up, there's usually a nice amount of fur on your pants. She'll occasionally shed clumps of fur, but she cleans herself a lot, so that might have something to do with it.