Hi,
I have been keeping a fuel log since I got my xA, and I have entered them into the EPA website. Here's the graph of all my tanks -- 178 of 'em so far!
The dips in the graph are during the winter -- I bought it in the late spring of 2005. At first I drove far fewer miles, so the beginning of the graph is compressed a bit in the horizontal/time. I started ecodriving and I did the significant aero mods that account for the latter part of the graph popping up well above the previous highs.