South Dakota Adult Population Grows, Youth Population Stagnates
According to the US Census Bureau, the South Dakota population continues to age and the trend shows no sign of reversing. The fraction of adults aged 65 and older has grown from 14.3% of the state's population in 2010 to 16.3% in 2017. In 2010, the adult population between the ages of 18 and 64 numbered 494,802 – 60.8% of the total population of 814,180. According to 2017 estimates, the total population is now approximately 869,666, with 59.0% of those counted between the ages of 18-64 –a 1.8% percent decline.
Over the same time period, the US Census Bureau reports that the relative number of younger South Dakotans has declined slightly. Children between the ages of 0 and 4 years old have gone from 7.3% of the population in 2010 to 7.1% in 2017. Similarly, the fraction of children between the ages of 5 and 17 years old has plateaued around 17.6% since 2010.
The 65 and older group grew more than any other age group in terms of absolute population change, increasing by 25,043 between 2010 and 2017, while the 18- to 64-year-olds grew by 18,384, the 0-4-year-olds increased by 2,138, and the 5- to 17-year-olds grew by 9,921.
The overall aging trend in the state is due to the aging of the “baby-boomer” generation, as seen in the growing number of senior citizens in the state. The oldest South Dakotans, those 85 and older, have been growing as a subset of the 65 and older cohort. The number of these most senior citizens increased from 19,226 in 2010 (2.4% of the state population) to 20,781 in 2017 (also 2.4% of the state population).
The statewide retirement-to-working-age ratio (the number of retirees divided by the number of working-age adults) indicates that retirees account for a growing percentage of the population. The retirement-to-working-age ratio in South Dakota rose from 23.6% in 2010 to 27.6% in 2017.
While the state as a whole appears to be aging, Census data indicates that some counties are much greyer than others. With a median age of 54.7, Custer County had the Rushmore State’s greatest number of older residents in 2017. In contrast, Todd County had the state’s youngest population with a median age of 23.9.