Partial pressure of oxygen in Mexico City?

Mexico City is at an elevation of 2240 meters (7350 ft) above sea level. The partial pressure of oxygen in Mexico City is lower than it is at sea level due to the decrease in atmospheric pressure with altitude. The partial pressure of oxygen in Mexico City is approximately 149 millimeters of mercury (mmHg), compared to approximately 159 mmHg at sea level. This means that the oxygen concentration in the air in Mexico City is about 10% lower than it is at sea level.