The y-axis is the win-lose difference.
The chart is base on the Results.

China

-8 -7 -6 -5 -4 -3 -2 -1 0 +1 +2 +3 +4 +5 +6 +7 +8 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 LGD Snake WE OP GEN.G JDG EDG.M Nova