Figure 5.

Geographic distribution of population size (male + female) and its impact on stability of SMR values. The fill color in each ZIP code represents the 2000 population size, with green indicating sparsely populated ZIP codes and purple representing larger population sizes (categories correspond to deciles of the histogram of sizes). The scatterplots illustrate the larger spread of measured SMR for ZIP codes with low population and how the extreme rates recorded in these ZIP codes are smoothed by geostatistical filtering.