Table B-4a. Estimated Measures of Reliability for Shipment Characteristics by Shipment Weight for the United States: 2012
(Estimates are based on data from the 2012 Commodity Flow Survey)
Average miles per shipment
coefficient of variation of number
|Coefficient of variation of number||Standard error of percent of total||Coefficient of variation of number||Standard error of percent of total||Coefficient of variation of number||Standard error of percent of total|
|Less than 50 lbs.||1.5||0.2||4.0||Z||4.0||Z||3.4|
|50 to 99 lbs.||2.8||0.1||2.3||Z||2.7||Z||2.4|
|100 to 499 lbs.||1.7||0.2||1.7||Z||2.5||Z||2.3|
|500 to 749 lbs.||2.3||0.1||1.7||Z||2.1||Z||1.9|
|750 to 999 lbs.||3.5||0.1||2.3||Z||2.6||Z||1.9|
|1,000 to 9,999 lbs.||1.7||0.3||2.3||0.2||2.0||0.2||1.8|
|10,000 to 49,999 lbs.||1.3||0.3||1.6||0.6||1.9||1.1||1.7|
|50,000 to 99,999 lbs.||4.3||0.3||2.9||0.5||3.3||0.2||2.5|
|100,000 lbs. or more||4.4||0.4||4.5||1.0||6.1||1.4||3.1|
KEY: Z = Rounds to zero.
(1) Ton-miles estimates are based on estimated distances traveled along a modeled transportation network. See “Mileage Calculations” section for additional information.
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: 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.