Fuel Tracking vs Euro/Dollar from Sept-April

I have been tracking my fuel consumption and came up with this chart (google docs + gadgets) that shows the trend from Sept last year to late April. I will update it with up to date data as soon as I can... Since I don't fuel daily (of course) the graph may appear spiked at some points.

Later, I am thinking of including the fuel stations I fuel at, and then mash this up with google maps to give a good idea of where to fuel in Nairobi (or not to fuel)..