Percentage of the Population in Age Groups
Between 2005 and 2013, modest changes occurred in the age distribution of both the Arizona and national populations. The proportions of adults between the ages of 35 and 44 decreased and between the ages of 55 and 74 increased, as the baby-boom generation (those born from 1946 through 1964) aged. The percentage of children under the age of 15 declined. The percentages fluctuate annually in Arizona, likely due to sampling error.