Estimates are based on data from the 2007 and 2002 Commodity Flow Surveys. Because of rounding, estimates may not be additive.
|Value (percent)||Tons (percent)||Value Standard Error of %||Tons Standard Error of %|
KEY: - = Zero or Less than half the unit shown; thus, it has been rounded to zero.
NOTES: Value-of-shipment estimates are reported in current prices. More information on sampling error, confidentiality protection, nonsampling error, sample design, and definitions may be found at http://www.bts.gov/publications/commodity_flow_survey/.
SOURCE: U.S. Department of Transportation, Research and Innovative Technology Administration, Bureau of Transportation Statistics and U.S. Department of Commerce, U.S. Census Bureau, 2007 Economic Census: Transportation Commodity Flow Survey, December 2009.