I've read at least 20 books each of the past two years...probably longer than that but I've only been keeping track since 2006. That said, I also go into spurts when I stop reading. If I am not diggin the book I am reading, I tend to put it down for days/weeks or even months at a time until I finally plow through it, or give up. Some books that I try to read just plain suck, so I quit and start a new one. When I fall into a slump, I pick up a King book and that will usually get me in the reading groove again. Also, I've always got an audiobook going these days on my iPod.
When I was in college, pleasure reading really suffered for me, like Chris said. I've currently got about 70 books that I own but haven't read and that number always seems to stay the same because I keep buying more.