aExport weights for land modes are estimated by the Bureau of Transportation Statistics using value-to-weight ratios derived from import data. bIncludes mail, other, unknown, and shipments through Foreign Trade Zones.
Percents do not add to 100 due to rounding. North American Free Trade Agreement (NAFTA) refers to U.S. trade with Canada and Mexico.
U.S. Department of Transportation, Bureau of Transportation Statistics, special tabulation and North American Transborder Freight Data, available at https://www.bts.gov/.
Last Updated: July 2018