|Mode or source||Volume of all oil spills (1991-2000)||Percent share of all spills (1991-2000)|
|Maritime nontank vessels and other||3,353,840||18.1|
|Waterborne tank vessels||6,907,500||37.3|
|Non-transportation structures and facilities||692,099||3.7|
|Unknown and other||1,261,849||6.8|
|Highway, aircraft, rail, and other||269,920||1.5|
NOTE: Data are preliminary.
SOURCE: U.S. Department of Transportation, Bureau of Transportation Statistics, calculations based on U.S. Coast Guard; Pollution Incidents in and Around U.S. Waters, available at http://www.uscg.mil/hq/g-m/nmc/response/stats/ac.htm, as of September 2002.