Nadal - 41.2%
Agassi - 28.9%
This is the highest AM we have for Nadal apart from the '08 Wimb QF over Murray. And Agassi's AM is pretty good, considering it's '06.
I knew Nadal played better grasscourt tennis in '06 than he is often given credit for, though I was not expecting to find an AM over 40%.