Table B-1b. Estimated Measures of Reliability for Export Shipment Characteristics by Export Mode: 2002 and 1997
[Estimates are shown as percents and are based on data from the 2002 and 1997 Commodity Flow Surveys]
|Export mode of transportation||Value||Tons|
|CV 02||CV 97||Std. error of percent change 1997-2002||CV 02||CV 97||Std. error of percent change 1997-2002|
|Air (including truck and air)||7.5||9.0||10.8||11.2||7.8||11.4|
|Parcel, U.S.P.S. or courier||11.0||8.3||21.6||31.4||27.7||28.4|
|Truck and rail||–||–||–||–||–||–|
|All other multiple modes||27.7||–||–||15.2||–||–|
|Other and unknown modes||13.8||6.8||4.5||28.6||24.6||11.4|
– Represents an estimate equal to zero or less than 1 unit of measure.
S Estimate does not meet publication standards because of high sampling variability or poor response quality.
CV Coefficient of variation of number
NOTE: 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/cfs.
SOURCE: Research and Innovative Technologies Administration, Bureau of Transportation Statistics (USDOT) and U.S. Census Bureau, 2002 Commodity Flow Survey, Export Data, March 2005.