I recreated some plots from a study Priscilla did for 2006. The plots represent differences between pedestal and rms values relative to a reference set, which from a table on January 26, 2008. The range covers 157 fills between run 8334001 (November 30, 2007) and run 9064017 (March 4, 2008).

The top left plot shows the difference between the pedestal and the reference pedestal.

The top right plots shows the difference between the pedestal and the reference pedestal divided by the reference rms.

The bottom left plot shows the difference between the rms and the reference rms.

The bottom left plot shows the difference between the rms and the reference rms divided by the reference rms.

BSMDE:

BSMDP: