The following chart shows federal outlays and revenues from 1940 to the proposed levels in 2009 as a percentage of gross domestic product (GDP). Gross domestic product is a measurement of the size of the economy. Viewing federal spending and revenues as a percentage of GDP indicates how large or small government is in relation to the economy.
 

Source: Office of Management and Budget, Budget of the U.S. Government, FY2009, Historical Tables.