What we don't know is the time frame the data is compiled. An early album may have the advantage of being released on 8 track, cassette and CD but for many it is old news by then. Some albums are never re-released on newer media. I just bought an old Jose Feliciano album on CD that had never been re-released in over 40 years. I still think the newer albums and movies have a much larger population with deeper pockets than ever before and to me that skews the data. HMO