And to see how much more is actually released, let's take a look at this graph. So, let's begin inside the lungs. So, inside the lungs, we basically have a concentration of oxygen of about 100 mercury. So the Y coordinate of all these three different curves is exactly the same. It's around zero point 98, which is equivalent to 98% saturation of hemoglobin. Now, when we go into the exercising tissues, the concentration of our oxygen drops to about 20 mercury.