Another noteworthy characteristic of racial disparities is their persistence over time. Table 3 presents infant mortality rates for blacks and whites, males and females, from 1940 to 2006.40 For both racial groups, there were marked declines in infant mortality over time, with the absolute difference in infant mortality in 2006 being only about one quarter of what it was in 1940. At the same time the relative difference in infant death rates for both males and females, increased from 1.7 in 1940 to 2.4 in 2006. For both racial groups, infant mortality has also been consistently higher for males and females. Trend data for heart disease and cancer -- the two leading causes of death in the United States -- indicate that blacks and whites had comparable death rates for these conditions in 1950, but that African Americans currently have higher mortality rates for both of these diseases than whites.41 Long term trend data is readily available only for blacks and whites. However, trend data exists for the 60% of the American Indian population served by the Indian Health Service
