US Table B–2b,,,,,,
"Estimated Measures of Reliability for Shipment Characteristics by Total Modal Activity for the United States: 2002 and 1997
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"[Estimates are shown as percents and are based on data from the 2002 and 1997 Commodity Flow Surveys]
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Mode of transportation,Ton–miles,,Std. error of  percent change,Average miles per shipment,,Std. error of  percent change
,CV,,,CV,,
,2002,1997,,2002,1997,
Total,3.7,2.3,5.3,2.8,2.6,4.3
Truck,2.8,1.7,4.1,3.6,2.8,4.9
Rail,7.6,5.3,11.3,6.1,2.6,6.6
Shallow draft,9.4,5.5,12.9,13.1,20.9,44.5
Great Lakes,18.1,14.1,29.5,16.0,10.8,17.7
Deep draft,17.3,17.3,26.2,11.1,13.0,19.2
Air,15.7,7.8,17.1,4.3,1.8,6.6
"Parcel, U.S.P.S. or courier",4.2,4.0,6.6,2.3,2.6,3.8
Pipeline,S,S,S,S,S,S
Other and unknown modes,9.7,8.5,7.8,13.0,9.6,17.2
"KEY: 
— Represents data cell 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.",,,,,,,,,
"NOTES: 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:  Bureau of Transportation Statistics (USDOT) and U.S. Census Bureau, 2002 Commodity Flow Survey, United States Data, December 2004.",,,,,,,,,
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