So there is this difference of about 10%. And what that tells us is when our cells of the tissue are exercising and therefore producing more H plus ions and so we have a lower PH. What the lower PH means is our hemoglobin will be more likely to actually unload that oxygen into those exercising cells inside our tissue. So the average partial pressure of oxygen in our tissues is around 40 mercury. Now, at lower PH values, when the cells of our tissue are exercising, we shift the curve to the right and this means we make the hemoglobin much more likely to actually dissociate and unload that oxygen into the exercising tissue. So this in turn will deliver more oxygen to those tissues because those cells of the exercise tissue will need more oxygen to produce more ATP in the process of cellular respiration.