Texas enrollments in the online insurance marketplace created under the Affordable Care Act rose nearly eightfold in December, according to 2013 figures that the U.S. Department of Health and Human Services released Monday.

Texas ranks third in the number of 2013 enrollments following the troubled launch of healthcare.gov on Oct. 1. As of Dec. 28, nearly 120,000 Texans had purchased coverage in the federal marketplace, up from 14,000 one month before.

The number represents a tiny fraction of the uninsured in Texas, which has a higher percentage of people without health coverage than any other state. In 2012, more than 6 million Texans, about 24 percent of the population, lacked health insurance, according to U.S. census data.

Florida led the nation in the number of 2013 enrollments, with 158,000. In a media call from Tampa, U.S. Health and Human Services Secretary Kathleen Sebelius praised Florida’s high enrollment numbers. Like Texas, Florida has a largely unfavorable political climate toward the Affordable Care Act, and a high rate of the uninsured, at 21 percent. HHS officials offered no explanation for why more people enrolled in some states compared with others.

“The numbers show that there is a very strong national demand for affordable health care made possible by the Affordable Care Act,” Sebelius said in the call announcing the enrollment data, adding that nationwide enrollment had reached nearly 2.2 million.

The data offers a first glimpse at demographic trends surrounding enrollment in the federal insurance marketplace. Texans between the ages of 18 and 34 accounted for 26 percent of those who signed up for coverage. Texans between 55 and 64 made up the largest demographic group of enrollees, at 29 percent.

Women of all ages constituted a majority of Texas enrollments: 55 percent. That was consistent with the nationwide trend. HHS officials said the trend was expected. Maternity care, newborn care and contraception are among the 10 categories of benefits that all health insurance plans must cover under President Obama’s health care law.

Enrollment breakdowns by race are not currently available, federal health officials said.

Three-quarters of Texans who purchased health plans in the exchange in 2013 received financial assistance, according to the HHS data. That percentage, which is less than the median rate of 80 percent for the 36 states operating under the federal exchange, might have been larger had Texas expanded Medicaid to cover poor adults. Texans living below the poverty line do not qualify for subsidies.

The Affordable Care Act requires most Texans to carry health insurance by March 31. The federal health law had a rocky start in October when the healthcare.gov website launched with major glitches. In past months, Sebelius has frequently apologized for the performance of the marketplace, but Monday’s announcement was a departure from the conciliatory tone.

“Americans are finding quality affordable coverage in the marketplace, and best of all, because coverage began on New Year’s Day, the promise and hope of the Affordable Care Act is now a reality,” she said.