The closing prices of Yahoo stock, adjusted for splits and dividends, for the final trading days of December 2010-2014 are given in the following table. The CPI for December of each year is also given (Yahoo Finance and the U.S. Census Bureau). Deflate the stock price series and comment on the financial performance of Yahoo stock.
Year................. Price ($)..................CPI
2010.................... 16.63................ 219.2
2011.................... 16.13................ 225.7
2012.................... 19.90 ................229.6
2013.................... 40.20 ................233.0
2014.................... 50.51 ................234.8