Do I count titles or number of books?

Rejoice and say goodbye to title counts as of 2005!  Count the number of books (volumes) the library owns.  For small to medium size libraries a title count is pretty much the same as a volume count.  A large library, however, may have many of copies of the same title (e.g. Harry Potter and the Sorcerer's Stone) and title counts would be somewhat smaller than volume counts.