Table B-3c. Estimated Measures of Reliability for Shipment Characteristics by Distance Shipped: 2002 and 1993
Table B-3c. Estimated Measures of Reliability for Shipment Characteristics by Distance Shipped: 2002 and 1993
[Estimates are shown as percents and are based on data from the 2002 and 1993 Commodity Flow Surveys]
Distance Shipped (Based on Great Circle Distance) | Value Coefficient of variation of number |
Value Standard error of percent change |
Tons Coefficient of variation of number |
Tons Standard error of percent change |
Ton-miles Coefficient of variation of number |
Ton-miles Standard error of percent change |
|||
---|---|---|---|---|---|---|---|---|---|
2002 | 1993 | 2002 | 1993 | 2002 | 1993 | ||||
All distances | 1.3 | 0.8 | 2.2 | 2.0 | 1.6 | 3.1 | 3.7 | 2.7 | 6.0 |
Less than 50 miles | 1.4 | 1.4 | 2.8 | 3.2 | 2.1 | 4.5 | 3.9 | 2.6 | 5.0 |
50 to 99 miles | 1.8 | 1.8 | 3.6 | 5.8 | 2.1 | 6.8 | 5.8 | 3.4 | 7.0 |
100 to 249 miles | 2.0 | 2.4 | 4.5 | 2.9 | 2.7 | 5.1 | 2.8 | 2.9 | 5.1 |
250 to 499 miles | 2.3 | 1.9 | 4.2 | 3.2 | 2.8 | 5.4 | 3.9 | 3.3 | 6.5 |
500 to 749 miles | 3.4 | 1.8 | 5.7 | 3.1 | 4.5 | 6.2 | 3.6 | 4.6 | 6.3 |
750 to 999 miles | 4.0 | 1.9 | 6.5 | 6.2 | 5.0 | 12.1 | 6.4 | 5.8 | 12.9 |
1,000 to 1,499 miles | 3.3 | 2.3 | 5.8 | 11.2 | 6.1 | 22.3 | 12.0 | 7.3 | 23.7 |
1,500 to 1,999 miles | 5.8 | 2.2 | 9.7 | 6.9 | 4.7 | 10.9 | 7.0 | 6.1 | 11.8 |
2,000 miles or more | 6.3 | 4.4 | 10.7 | 3.9 | 9.1 | 10.4 | 4.3 | 9.0 | 10.1 |
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.
NOTE: The Introduction and appendixes give information onf 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.