[Estimates are based on data from the 2002 Commodity Flow Survey. Because of rounding, estimates may not be additive]
– Represents an estimate equal to zero or less than 1 unit of measure.
S Estimate does not meet publication standards because of highly sampling variability or poor response quality.
Bureau of Transportation Statistics (USDOT) and U.S. Census Bureau, 2002 Commodity Flow Survey, Hazmat Data, December 2004.