|Mode||Value (percent)||Weight (percent)|
|Other and unknown||4.5||0.1|
|Other and unknown||3.7||0.1|
|Other and unknown||5.5||0.2|
Sources: U.S. Department of Transportation, Bureau of Transportation Statistics, June 2001; based on: total, water, and air data-U.S. Department of Commerce, U.S. Census Bureau, Foreign Trade Division, U.S. Exports of Merchandise, CD-ROM and U.S. Imports of Merchandise, CD-ROM, December 2000; truck, rail, pipeline, other and unknown data-U.S. Department of Transportation, Bureau of Transportation Statistics, Transborder Surface Freight Data, 2001; and special tabulations.