No easy way, as the vertical scale only goes to 100 Wh and sometimes the bars go over that value (see the triangle at the to of the bar?). Besides data being cut off, you could add up all of the bars to come up with a total Wh recuperated during your drive, and convert that to kWh recuperated. But, since the trip efficiency takes into account energy used and energy recuperated, you are going to have a tough time figuring out how many miles of range you recovered without knowing how much energy exited the battery during your trip - maybe you can find this somewhere though OBD? In short, the answer is no, you can't come up with a formula to calculate miles recovered based on this graph.
