Ayu's Sales

[mowbli]

Hi, I don't know if this has been posted before and I apologize if it has, but how many records has Ayumi actually sold? Wikipedia says 50 million, but provides no source. And in one page it says Ayu's combines sales of singles and albums reached over 6 million in 2000 and another says she sold 10 million records that year. Does anyone know for sure and have links to prove?