The population of Arizona is heterogeneous (Figure 4.1), though whites compose 72 percent of the population. The second largest segment of the population is made up of people of Spanish heritage. That group constitutes 18.7 percent of the population, but some argue that this figure is too low, for many persons in this group are not counted, particularly the illegal aliens who made an understandably determined effort to avoid enumeration. The third largest group, the Indians, composes 5.6 percent of the population, and the blacks, 3 percent. The remainder of the population, classified as "other," is figured at 0.7 percent of the overall population.