Is there a list that shows position changes between the last update and the current update? I'd like to see how much some songs have risen or fallen.

Also, I've been wondering, what causes some songs/albums to take massive plunges? Do certain lists get replaced in the formula, such as best of all time lists from the same source? I don't get how some songs stay near the same level while some drop hundreds of spots.

The Excel file on the homepage shows this, including exactly how many places a song rose or fell from the previous update.

As to explain some of the big drops in the last update, I made some decisions prior to the albums update laste year, that have now also taken effect in the songs list. I have excluded all end of year lists from Iguana (which is a single critic) and lowered the weight for some critics lists that no longer exist on the web. Some of these are even debatable whether they were made by critics (Pure Pop, Movement). I have also completely removed an all time list from a single critic (John Grooms) that I found many years ago, but I never entered the complete list into my spreadsheet and now it's not available anymore.