deflator
From Longman Business Dictionarydeflatorde‧flat‧or /ˌdiːˈfleɪtə, dɪ--ər/ noun [countable]ECONOMICSSTATISTICS in calculating economic statistics, something that is used to remove the effect of INFLATION from the figures so that figures from different periods of time can be comparedThe broadest measure of inflation, the implicit price deflator for the gross domestic product, fell from 2.2 percent in April to 2.1 percent this month.