I didn't keep track of how many books I read last year. I got a Nookcolor in August so I stepped up my reading with that.
However, all books are not the same - some are easy reads and go fast, some are more difficult and go slower. My boys have to read a certain number of pages each quarter for school, regardless of how many books. So I might have to go that way - number of pages. Just to make myself feel better.
ETA: I wanted to put my goal on Goodreads, so I have to choose number of books. According to that, I read 23 since I got my NC in August, so I put 40 for this year, since there are months where I'm too busy to do anything extra, like read.