Income seems to play an important role in the relationship to cumulative AIDS rates as well. When correlated with cumulative AIDS rates in Allegheny County, the percent of households earning less than $10,000 annually supplied a coefficient of 0.53 which proves significant at both the 95% and 99% confidence intervals (Tables 1.1, 1.2; Graph 1.1; Maps 1.1, 1.2). Furthermore, when Pittsburgh AIDS rates are correlated with average median household income (median household income for each zip code divided by median household income for Allegheny County), the correlation coefficient of -0.483 proves to be significant (Table 1.1, 1.3; Graph 1.2; Maps 1.1, 1.5). These numbers are all under the assumption that “a household includes all the people who occupy a housing unit as their usual place of residence,” and therefore can be used to indicate AIDS patterns in relationship to income (United States Census Bureau). The correlations presented further demonstrate how AIDS cases are less common in wealthier areas, and in turn, are more common in impoverished residences. From these correlations it is clear that income, or lack thereof, does play some central role in cumulative AIDS rates for Allegheny County.