
1 Primarily container vessels.
2Tramp or nonscheduled service.
SOURCES: U.S. Department of Transportation, Maritime Administration, Office of Statistical and Economic Analysis, U.S. Imports and Exports by Customs District Ports, U.S. Foreign Waterborne Transportation Statistics," available at http://www.marad.dot.gov/statistics/usfwts/index.html, and U.S. Foreign Waterborne Commerce, adapted from U.S. Department of Commerce, U.S. Census Bureau, U.S. foreign waterborne commerce data, various years.