I run all of my hashing power through gpumax and imsaguy is correct. There has not been much public work. Us "in the know" call it leasing.
Okay... does this mean you are getting fresh coins?
That's the main point actually. Is there a lot of hashpower used on work that is paid with coins that have history? How big is the fraction of clean or relatively new coins?
Edit: "I run all of my hashing power through gpumax" is the important part here -- so they control which coins you get, no?