Americas transportation system continues to change along with the population, work force, and economy. The following table puts those changes in perspective:
|Resident population (thousand)||248,791||304,060|
|Total area (thousand sq. mi.)||3,718||3,794 (2000)a|
|Total civilian labor force (thousand)||125,840||154,287|
|Real gross domestic productb (trillion)||$8.0||$13.3|
|Median household incomeb,c||$41,465||$46,370|
|Average household incomeb,c||$44,160||$58,594|
|Average household expendituresb,c||$39,338||$46,304|
|Number of households (thousand)||93,347||117,181|
|Life expectancy at birth (years)d||75.4||77.7 (2006)|
a Data for 2000 include inland water, coastal water, Great Lakes, and territorial water. The Census Bureau tabulates area data for the decennial census years only. b Data in 2005 chained dollars (see Glossary for definition). c BTS computations, November 2009. d Life expectancy for 2000-2006 were calculated using a revised methodology and may differ from previously published data.
Sources: AreaU.S. Department of Commerce (USDOC), U.S. Census Bureau, Statistical Abstract of the United States: 2002 and 2009, available at www.census.gov as of November 2009. GDPUSDOC, Bureau of Economic Analysis, available at www.bea.gov as of November 2009. Population, number of households, and median household incomeUSDOC, Census Bureau, available at www.census.gov as of November 2009. Average household income and expenditures, and labor forceU.S. Department of Labor, Bureau of Labor Statistics, available at www.bls.gov as of October 2009. Life expectancyCenters for Disease Control and Prevention, available at www.cdc.gov as of September 2009.