NOTE: GDP can be classified into services, goods,
Services include government consumption expenditures, which are for services (such as education and national defense) produced by government.
Structures include fixed assets such as roads, railroad tracks, airports, power plants, and medical buildings.
Goods include all goods consumed as final demand.
SOURCE: GDP dataU.S. Department of Commerce, Bureau of Economic Analysis, National Income and Products Account (NIPA), available at http://www.bea.gov/bea/dn/nipaweb/index.asp, as of February 2004.
Ton-miles dataU.S. Department of Transportation, Bureau of Transportation Statistics, National Transportation Statistics (online: February 2004).
Population dataU.S. Department of Commerce, Census Bureau, available at http://eire.census.gov/popest/archives/pre1980/popclockest.txt, as of February 2004.