Tonnage of U.S. waterborne imports and exports (monthly, not seasonally adjusted)
|Metric tons (thousands)|
NOTES: Import and export tonnage helps identify the volume of cargo flowing through U.S. ports and the resulting vessel traffic on U.S. coastal waters. It also helps identify needs for intermodal truck and rail traffic. Most U.S. coastal ports handle both foreign and domestic cargoes.
A metric ton is equal to 2,204.6 pounds.
SOURCE: U.S. Department of Commerce, U.S. Census Bureau, Foreign Trade Statistics, FT920 - U.S. Merchandise Trade: Selected Highlights, Exhibit 3 and Exhibit 9, available at http://www.census.gov/foreign-trade/statistics/index.html as of December 2010.