Coparing census demographics from different census years can be a difficult task due to changing geographic boundaries. Our normalized data product line assists researchers with comparisons of data across time by adjusting and weighting the census data to account for changes in geographies.
To demonstrate some of the issues associated with changing boundaries, below is a comparison of Pima County, Arizona in 1990 and 2000 at the Census Tract level. During this time span, Pima County expanded in population. A quick appraisal of the two maps below demonstrates the numerous changes that occurred in the census tract boundaries, specifically the addition of 83 tracts in 2000.
Pima County, AZ
Total Census Tracts (115)
Pima County, AZ
Total Census Tracts (198)
Discounted Demographic Data Packages with Normalized Data. We also have Demographic Data Packages that include both combinations of normalized and non-normalized datasets:
- Time Series Research Package. This package is our most complete package with normalized and un-normalized census data from 1970, 1980, 1990, 2000, and now 2010. If you need instant access to all the data, this is the best discounted package that covers a broad range of our demographic data product line.
- Planners Package Plus. This combination of products was put together for planners, developers, and marketing in mind. It covers 1990 and 2000 normalized data to 2010 boundaries, 2010 Census data, and the last piece is the current year population estimates and 5-year population projections.