Seeing a change in the numbers of cases in various categories across reports is therefore expected. Both proportions are higher than usual. The demographics, therefore, is constantly changing. An incidence rate is defined as the rate at which new events occur in a population.
Incidence rates allow comparison of disease patterns across different populations.
However, in 1999, there was a slight increase among Hispanics, as captured in the figure. Although the AIDS incidence rates among Hispanics remains only slightly above the County average as a whole, the incidence rates among African Americans remains significantly higher than the County average. This often means that at the time of reporting, one of the risk factors as defined by CDC was not identified for these cases.