Census tract
Census tract means a population census tract, or, if census tracts are not defined for the area, a block numbering area (BNA) as established by the Bureau of the Census, U.S. Department of Commerce. BNAs are areas delineated by state officials or (lacking state participation) by the Census Bureau, following Census Bureau guidelines, for the purpose of grouping and numbering decennial census blocks in counties or statistically equivalent entities in which census tracts have not been established. A BNA is equivalent to a census tract in the Census Bureau's geographic hierarchy.