[Estimates are shown as percents and are based on data from the 2002 and 1997 Commodity Flow Surveys]
– 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.
CV Coefficient of variation of number
NOTE: The Introduction and appendixes give information on confidentiality protection, sampling error, nonsampling error, sample design, and definitions. Links to this information on the Internet may be found at www.census.gov/cfs.
SOURCE: Bureau of Transportation Statistics (USDOT) and U.S. Census Bureau, 2002 Commodity Flow Survey, Hazmat Data, December 2004.