When I look at all the completed loans for 2010 using the excellent NSR platform, the ROI for all unfiltered loans is 6.09%. When I look at the same at the Lending Club site, the "Adjusted Net Annualized Return" is 6.69%. Several other numbers match or are very close, including the total issued and average interest rate. Why the significant difference? I'm assuming it's in the ROI calculation, but if so, which is more accurate?