Sorry for the omission, my data was in mph, from gps of course.

I don't think it's a given that there's a 100kt headwind at cruise. Of course, there just might have been one that day.Cruise was FL320.

I think the poster who thought there's an optimum cruise speed was wrong, but it's not my specialty so I actually don't know. I believe I'd read a few years ago in another fuel-price spike that one or more airlines were flying more slowly to save fuel, but that could have been urban legend too. In any case my gut feel is that there's a non-linear increase in fuel consumption with speed.