Measuring Worth This link opens in a new windowCollection of publicly available high quality and the most reliable historical economic data on nominal (current-price) measures and real (constant-price measures). Data presented here covers the United States, United Kingdom, Australia, and Spain. Examples of featured data sets cover topics such as Gross Domestic Product (GDP), Consumer Price Index (CPI), wages, earnings, interest rates, stocks, and currency exchange rates with coverage of these items varying from county-to-country.