Carbon dioxide transport

[pegasus10]

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!

[studiot]

Perhaps this respiratory diagram will help.

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