I am currently trying to convert some Chinese CPI Data. The data I have ranges from 2001 to 2011 and is monthly. The base period is (Previous Year = 100), which means that it assumes the month of the previous year is 100 and then calculates the change of this same month this year. So if March 2011 says 105, then it means that it took March 2010 as 100 and that the growth from that monthly period to now is 5%. I wish to instead let 2005 = 100 and to let all the prices reference that period. Is this possible? Thanks!