This relationship file contains the population, housing unit count, total area, and land area for each unique 2010 urban area-2000 urban area combination; the population, housing unit count, total area, and land area of the entire participating 2010 and 2000 urban area entities; and the percent population, housing unit count, total area, and land area that each combination represents of the entire participating 2010 and 2000 urban area entities.

For records corresponding to parts of or entire 2000 urban area entities that do not overlap any 2010 urban area, the 2010 urban area code is 99999, the 2010 urban area name is “Not in a 2010 urban area”, and the 2010 urban area population, housing unit count, total area, and land area values are null. The percent values relating to the 2010 urban area are also null.

For records corresponding to parts of or entire 2010 urban area entities that do not overlap any 2000 urban area, the 2000 urban area code is 99999, the 2000 urban area name is “Not in a 2000 urban area”, and the 2000 urban area population, housing unit count, total area, and land area values are null. The percent values relating to the 2000 urban area are also null.

Note that in order to make the percentage fields in this relationship file meaningful, the population and housing for the 2000 urban areas are expressed in terms of 2010 population and housing. Therefore, the UA00POP and UA00HU for a particular urban area will not match the official 2000 population and housing values for the 2000 urban area.

Area measurements are in square meters.