South Dakota's median age in 2015 was 36.9, making it the 37th oldest of the 50 states. This compares to No. 1 Maine, at 44.5, and No. 50 Utah, at 30.7.
The percentage of South Dakota's population under age 18 has been steadily declining since at least 1990, when it was 28.5 percent, compared to 24.6 percent in 2015.
Between 2010 and 2015, South Dakota's population grew faster than the nation as a whole - a first in a half-a-century. South Dakota's growth rate of 5.4 percent compared to the national rate of 4.1 percent.
More than 147,000 South Dakotans were people of color in 2015. This accounts for 17.1 percent of the state's population and continues a trend of healthy annual increases since 1990, when 8.5 percent of South Dakotans were of color.