Here is the total winner/UE for the 4 slams:
AO: 6821 / 6966
RG: 9363 / 9172
W: 10241 / 6182
USO: 7278 / 7077
Odd that AO has more unforced errors than winners. More evidence that AO is ridiculously slow. Anyway I think they should speed up the faster surfaces just a bit, there should be a lot more winners then unforced errors.