Charlie, I'll do my best. I was not at Miller, and did not see every dyno there, so those years are less clear.
2007 - 137, 135 (few dynos done)
2008 - 139 (first "pro-built" motor), 137 (still few dynos, second pro built motor blew up before tested)
2009, 2010 (Miller) 143, 139 (may be others)
2011 - 139, 138, 135
2012 - 141, 140.5, 136
With Nationals back at Miller, we expect a bigger turnout, and a bigger number of highly tuned cars for 2013.
This only represent cars that showed up at Nationals, not all the dynos we see and evaluate.
What question do have on the formula?
At the suggestion of John Brown, I changed how it was typed to be more mathematically correct, but it should be clear.