I recently got access to some very comprehensive data from the EU funded ENUMERATE project. They asked almost two thousand cultural institutions in Europe how much of their content is actually digitised and how much should still be. Unfortunately, they had to anonymise the names of the institutions but there still is lots of info you can get out of this. I quickly made for example this chart with Many Eyes that shows that 50% of all institutions have 0-10% of their collection digitised.
Now, there is a lot of stuff wrong with this chart but it shows the possibilities. I was wondering if anybody would be interested in working to create a couple of better ones. Please let me know.