Currently the CPI indices are referenced to 2005=100 (ie for each component, the average of the monthly indices of that year are set to equal 100). For the release of January consumer price inflation data on 16 February 2016, CPI and CPIH indices will be re-referenced and published with 2015=100. Please note that that this will not impact on published inflation rates. Re-referencing does not impact on RPI and RPIJ. The historical back series for CPI and CPIH 2015=100 is now available for users to view or download.