And notice that at this particular point, we have three different Y coordinates. For this black curve, the Y coordinate is around zero point 32. For the blue curve, the coordinate is around zero point 21. And for the red curve, the corden point is around 0.1. And what that means is, for that black curve, when we have a PH of 7.4 and no carbon dioxide present inside our exercising tissues, the hemoglobin will be 32% saturated with oxygen. However, if we drop the PH to about 7.2, and once again, no CO2 is present, now, in the exercising tissues, the hemoglobin will be able to unload more oxygen, because our fractional saturation drops.