Sadly, my french is even worse than my engrish
Err I guess it's because that one source just happens to have lower values? I'll try to give an analoge example:
I know people donate on average 50$ to charity, which gives them a tax benefit of 30% of that 50$; population is 500 000
In my sample, people of one region donate on average 37$ to charity, which gives them a tax benefit of 25% (benefit is unrelated to region, i'm just saying region instead of that one provider) on that 37$; sample size is around 1300. I can calculate mean, deviation, range (of donation size) etc from