The proportion of U.S. adults without health insurance has declined about 6.1 percentage points since fourth-quarter 2013, to 11%, according to a Gallup analysis of the Gallup-Healthways Well-being Index survey for first-quarter 2016. Hispanic and African-American adults, young adults and those earning less than $36,000 a year saw the greatest declines. Open enrollment in the 2016 Health Insurance Marketplaces ended Jan. 31.