Has the calculation of pensions increase changed?

Before April 2011, Pensions Increase was based on the increase in the Retail Prices Index (RPI) during the twelve months to the September of the previous year. However the Budget Statement of 22 June 2010 announced that from April 2011, the Consumer Price Index (CPI) replaced RPI as the measure of inflation used to apply cost of living increases. The CPI has been used from April 2011.