Now, this is not the important point. The important point lies in this line. So when our tissue is exercising, its partial pressure of oxygen can drop to as low as 20 mercury. So let's suppose this is the partial pressure of our oxygen inside the exercising lines, inside the exercising tissue. And if we draw a straight vertical line upward and now we check the corresponding Y values for both of these curves, this is where our difference will actually lie. For the case of hemoglobin, we see that at 20 mmhg, our saturation, percent saturation is equal to about 32%.