In the new improved 10-year financial page on GuruFocus, the stock's historical Shiller P/E ratio was added. When we calculate today's Shiller P/E ratio of a stock, we use today's price divided by E10. If we want to calculate the E10 of Walmart ( WMT ) for Dec. 31, 2010, we need to have the inflation data and the earnings from 2001 through 2010.