Table B-1a. Estimated Measures of Reliability for Export Shipment Characteristics by Export Mode of Transportation: 2012
(Estimates are based on data from the 2012 Commodity Flow Survey. Because of rounding, estimates may not be additive)
|Export mode of transportation||Value||Tons|
|Coefficient of variation of number||Standard error of percent||Coefficient of variation of number||Standard error of percent|
|Air (includes truck and air)||4.4||1.1||7.7||0.1|
|Parcel, U.S. Postal Service, or courier||7.9||0.2||6.7||Z|
KEY: S = Withheld because estimate did not meet publication standards.
Z = Rounds to zero.
(1) “Truck” as a single mode includes shipments that were made by only private truck or only for-hire truck.
(2) Estimates for pipeline exclude shipments of crude petroleum (SCTG 16).
NOTES: Value-of-shipments estimates have not been adjusted for price changes. Appendix B tables provide estimated measures of sampling variability. The Introduction and appendixes give information on confidentiality protection, sampling error, nonsampling error, sample design and definitions. Links to this information on the Internet may be found at <www.census.gov/econ/cfs>.
SOURCE: U.S. Department of Transportation, Bureau of Transportation Statistics and U.S. Department of Commerce, U.S. Census Bureau, 2012 Economic Census: Transportation Commodity Flow Survey, December 2014.