Prosper needs to update Debt Sales data. They don't show any historical data past 2007:
Dec 2007
701 loans sold
12.5%: Homeowners
9.6%: Non-homeowners with AA and A credit grades
9.1%: Non-homeowners with B, C, and D credit grades
7.3%: Non-homeowners with E and HR credit grades
4.8%: Non-homeowners with NC credit grades
3.5%: Texas residents
Aug 2007
309 loans sold
23.0%: Weighted average price for AA and A credit grades
13.3%: Weighted average price for B, C, and D credit grades
8.1%: Weighted average price for E and HR credit grades
May 2007
294 loans sold
16 - 19%: Homeowners
2.4 - 3.3%: Non-homeowners
Dec 2006
51 loans sold
27 - 30%: Homeowners with any credit grade
15 - 18%: Non-homeowners with a credit grade of D and above
3.0 - 3.7%: Non-homeowners with a credit grade of E and HR