Based on those figures, you'd think the UMP gained seats in 2007, whereas in reality the right (which was already quite consolidated - and dominated by the UMP - in the second round) consolidated further in the first round where it didn't really matter, while on the left the Socialists probably faced stronger challenges from the far-left in in the first round this time around (again, likely not enough in many hopeful constituencies to keep them out of round 2) - but these forces seemingly rallied behind them in the second round. Plus I am sure the percentage for parties on the "left" increased significantly between the first and second rounds, with several seats swining from the "notionals" obtained by combining the totals for candidates generally considered to be on the right and left, with the MoDems not being counted in either category. So France's two-round system seems to give the far left a chance to vent - which they may be taking greater advantage of, although the Commies lost ground in both rounds - and the right bragging rights for the period of time between the two rounds.
I'm not saying this would be the result, I'm saying these would be the results if only the first round had counted. Of course, people would've voted differently, maybe MUCH differently if France used an FPTP system. The far-left, which I don't consider the PCF part of (and most French analysts agree with me here), does relatively good scores (3,41%) in first rounds, but a LCR/LO/PT candidate rarely reaches the second round.