Us zip code washington
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if all the codes of a number type (i.e., 1s = 1.0 and 1.1, 2s, 4s etc.) represent 66.67% of the population, the larger of the subcodes was assigned (e.g., 1.0).if one code (x.x) represent 66.67% or more of the population, it was assigned.The assignment algorithm consisted of the following rules (the rules are in order and once a ZIP is assigned with a rule it is not considered further): A retrospective combining of the rules would reduce their number, although the order often deliberately assures that a more appropriate code is assigned.
#Us zip code washington trial#
The assignment algorithm was developed through trial and error and progressively developed assignments by rules. A clear example would be a ZIP code in which 95% of the population was in RUCA code 7.0 Census tracts and 5% was in RUCA code 8.0 – wherein the ZIP would be assigned as a 7.0. A RUCA assignment algorithm was developed that assigned each ZIP code a RUCA code based on the distribution of its population across the RUCA codes. For example, if a ZIP code area had four Census tract segments each of which had a population of 4000 and two of them were RUCA Census tract assigned 1.0, one was assigned 1.1, and one was assigned 2.0, the file would show ZIP code number, 8000 population for 1.0, 4000 population for 1.1, 4000 population for 2.0, zero population for 2.1, and zero for each of the remaining rubrics.ĥ. A file was created where each residential ZIP code had its estimated segment populations aggregated by the 33 RUCA codes. Each Census tract was assigned a RUCA code as explained in the section on Census tract RUCA methodology, which used Census Bureau definitions of Urbanized Areas and Urban Clusters and work commuting flows based on the 2000 Census results.Ĥ. For such a ZIP code, the file would contain a population estimate for each of the four segments.ģ. For instance, a ZIP code area might have its boundaries crossed by four Census tracts. identified their 2004 estimates of the populations of all ZIP and Census tract segments. A ZIP/Census tract crosswalk file from Claritas Inc. 2004 residential and commercial ZIP code information were obtained from Claritas Inc.Ģ. The RUCA ZIP code approximation was the result of the following generalized analytical steps:ġ. The ZIP code approximation is based on the Census tract codes and are not based on commuting data unique to the ZIP code geographic unit. Because the smallest geographic identifiers available for most health care data sets are ZIP codes, a ZIP code approximation of the Census tract-based RUCA codes was developed.