I understand you want to compare total sales, but you can't just ignore the staggered launch.
10 months in one region plus 1 month in two regions is VASTLY different from 13 months in two regions plus 9 months in one region. There's just no way you can ignore that. I'm not saying you should use 1 month in two regions as PS3s first year either btw.
Let me make it clear. The only valid way to compare the two consoles is by region. 2001 vs 2008 is an interesting comparison, that I like to see being made, BUT it is NOT a comparison of the second year for each console since it isn't really the second year for either console. Calendar years simply don't work out.