Table B-1c. Estimated Standard Error of Percentage for Export Shipment Characteristics by Export Mode: Percent of Total for 2002 and 1997
Table B-1c. Estimated Standard Error of Percentage for Export Shipment Characteristics by Export Mode: Percent of Total for 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 | ||
---|---|---|---|---|
Std. error of percent 2002 | Std. error of percent 1997 | Std. error of percent 2002 | Std. error of percent 1997 | |
All modes | – | – | – | – |
Single modes | 1.3 | 1.0 | 1.0 | 1.8 |
Truck | 1.9 | 2.2 | 1.6 | 0.7 |
Rail | 0.3 | 1.2 | 1.9 | 1.6 |
Water | 1.0 | 1.4 | 3.2 | 2.3 |
Air (including truck and air) | 1.3 | 2.8 | 0.2 | 0.2 |
Pipeline | S | – | S | – |
Multiple modes | 1.5 | 0.3 | 0.9 | 0.1 |
Parcel, U.S.P.S. or courier | 0.5 | 0.3 | – | 0.1 |
Truck and rail | – | – | – | – |
All other multiple modes | 1.5 | – | 0.9 | – |
Other and unknown modes | 0.3 | 0.8 | 0.4 | 1.7 |
KEY:
– 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.
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.