The Reserve Bank Act requires that price stability be defined in a specific and public contract, negotiated between the government and the Reserve Bank. This is called the Policy Targets Agreement (PTA). The current PTA, signed in September 2012, defines price stability as annual increases in the Consumers Price Index (CPI) of between 1 and 3 percent on average over the medium term, with a focus on keeping future average inflation near the 2 percent target midpoint.