The graph shows individual fuel-ups that have a calculated MPG. You have several fuel-ups marked partial. And if you take a look at the
FAQ entry for partial fuel-ups you'll see that those fuel-ups do not have a calculated MPG, and the fuel-up immediately after does not have a calculated MPG. Fuelly needs a full tank to work from to calculate a MPG for an individual fuel-up.
Once you have a few full fuel-ups in a row the graph will update.
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