The link below is to an article that looks at the number of books on bookshelves that are unread and more than likely they will never be read.
For more visit:
http://www.telegraph.co.uk/culture/books/booknews/10679079/Half-of-books-in-homes-are-unread.html
At the BookShelf 
I have about that many just unread and despite making an effort not to buy new ones I don’t seem to be making great inroads.