Hello, talking about CO2 transport, we know that the T form of hemoglobin binds more CO2 as carbamate than does the R form, so when the concentration of CO2 is high, the T state is favored and hemoglobin releases its bound O2. This mechanism is pretty clear to me, but I can't understand a statement made by my textbook when explaining this concept: "Although the difference in CO2 binding between the T and R states of hemoglobin accounts for only 5% of the total blood CO2, it is responsible for around  50% the CO2 transported by the blood. This is because only 10% of the total blood CO2 is lost through the lungs in each circulatory cycle".

Can someone explain this sentence in different words?

Thanks in advance!

Perhaps this respiratory diagram will help.

Don't forget that the partial pressures of the blood gasses also depends upon the pH.