The CCDs are subcounty areas that can be summed to approximate the current boundaries of each county. These approximate 1980 boundaries are not identical to the 1990 county boundaries. However, the boundary errors are fairly minor and occur in relatively unpopulated areas. Therefore, the 1980 data for the approximated counties are reasonably comparable to the 1990 data for the actual counties. The sum of Fence Lake, Grants, Laguna and Zuni-Ramah CCDs approximates Cibola County, while the Belen and Los Lunas CCDs approximate Valencia County.
Figures are percentages of the total population.