Alaska had one of the lowest four-year graduation rates in the United States in the 2013-14 school year, according to data released Tuesday by the U.S. Department of Education.

That year, 71.1 percent of Alaska's high school seniors graduated in four years -- the rest dropped out or needed more time to get their diplomas. Alaska's four-year graduation rate topped only that of Washington, D.C., Nevada and New Mexico, according to the department's data.

Nationwide, the four-year high school graduation hit 82.3 percent, a rate that U.S. Secretary of Education Arne Duncan said in a press release was a record.

The nationwide graduation rates, broken down by race and selected demographics, ranged from 89.4 percent for students classified as Asian/Pacific Islanders to 62.6 percent for English-language learners.

In Alaska, the rates ranged from 32.2 percent of English-language learners graduating in four years to 78.5 percent of white students. About 42 percent of students with disabilities graduated in four years, as did 59.6 percent of students characterized as economically disadvantaged and 54.9 percent of Alaska Native students.

In the 2014-15 school year that followed, Alaska's four-year graduation rate increased to 75.7 percent -- up from 68 percent in 2011. Superintendents and the state education department said the rate was boosted by the elimination of the high school exit exam, which students once had to pass to get their diplomas. The Legislature eliminated that exam in 2014.