KEY: dwt = deadweight tons.
NOTE: Calls are by oceangoing vessels of 10,000 dwt or greater at U.S. ports, excluding Great Lakes ports. 1998 is the first year for which data are available.
SOURCE: U.S. Department of Transportation, Maritime Administration, Office of Statistical and Economic Analysis, Vessel Calls at U.S. Ports 2002–2003 (Washington, DC: 2004), table S-1.