And let's suppose we're going from the lungs to our resting tissue. So the lungs have a partial pressure of 100 mercury, and the corresponding Y value at this point is about zero 98. So that means about 98% of the hemoglobin is fully saturated inside our lungs. Now, when the hemoglobin travels down to our resting tissue, which is at a pressure of about 40 mercury, the corresponding Y value is about zero point 77. And that means about 77% of that hemoglobin is fully saturated with oxygen inside our resting tissue. Now, what that tells us is when the hemoglobin goes from the lungs to the resting tissue, there is a difference of about 21%.