Hypertension Prevalence and Control Among Adults: United States, 2015-2016
https://www.cdc.gov/nchs/data/databriefs/db289.pdf
The overall hypertension rate was 29% and increased with age from 7.5% for ages 18-39 up to 63.1% for those 60+. Also looks at differences by races and gender. From the National Center for Health Statistics