The country’s uninsured rate dropped nearly 5 percent in one year under ObamaCare, falling to a low of 12.9 percent last month, according to a new Gallup poll.

The rate of Americans without health insurance plunged sharply from 17.1 percent at the start of 2014, which marked the first year that the healthcare law’s individual mandate went into effect.  

African-Americans and Hispanics gained coverage at higher rates under the healthcare law, according to the polling data. The uninsured rate among those populations dropped 7 percent and 6.3 percent, respectively, over the last year.

The differences were also stark among Americans who made less than $35,000 per year and young people between the ages of 18 and 25, which also saw rates fall 6 percentage points or more.

The new numbers are good news for the Obama administration, which is just beginning to fight off new attacks against its healthcare law under the GOP-controlled Congress.

Still, the Gallup data shows a slightly higher uninsured rate than the 11.3 percent figure released by the National Center for Health Statistics’ National Health Interview Survey last month. The White House Council of Economic Advisers (CEA) used that figure to predict that the nation’s uninsured rate was “at or near the lowest levels ever recorded.”

The type of insurance used by most Americans has also changed over the last year, with more people paying for their own plans or using Medicaid. The rate of people with self-paid plans rose to 20.6 percent in the final months of 2014, up from 16.7 percent at the same time last year.

The individual mandate went into effect in January 2014 for a majority of Americans, though people will see the financial penalties for lacking coverage for the first time this tax season.

ObamaCare’s employer mandate goes into effect for the first time in 2015, which Gallup methodologist Jenna Levy said could further drive down the uninsured rate. More people could also gain insurance if more states expand their criteria for Medicaid, the government’s low-income insurance program, she wrote.

The figures are based on surveys with 43,000 people across the country. The uninsured rate is the lowest since Gallup began tracking it in 2008.