I agree with Papaver. It is entirely impossible to compare one year's tour with another. Not only are the distances different, the number and difficulties of the climbs change, the weather conditions change, the race conditions change. Just how motivated the sprinters teams are to keep the pace high on the flat stages could make a HUGE difference in the total time a TDF takes a particular rider to finish the whole tour without having anything at all to do with that rider personally - he was just staying in the pack... Even if you were to somehow find the same stage from different years and try to compare it wouldn't work - it all depends on what the tactics were for the day - sometimes they ride very hard, but at other times they intentionally slow it down. The only time you'll find any one rider ride all out every time is for a TT - and then only if they are looking to either win it or keep/better their overall position (even in a TT, sometimes the pure climbers/sprinters and domestiques will only do enough to not be time cut...)