Many of the nation's seniors have failed to make serious gains in reading and math in recent years, according to test results released Wednesday.

About 92,000 seniors from 13 states took the National Assessment of Educational Progress (NAEP) in 2013. Minnesota students did not participate.

The results show that seniors scores in both test subjects were relatively unchanged when compared to 2009. But math scores have improved since the test was first administered in 2005. Reading scores have dropped since 1992, the first date the NAEP test was given to seniors.

Overall, about 26 percent of the seniors who took the test are proficient in math and 38 percent in reading, results show. Achievement gaps between white students and students of color also persist on the test.

U.S. Education Secretary Arne Duncan expressed disappointment with the scores.

“Despite the highest high school graduation rate in our history, and despite growth in student achievement over time in elementary school and middle school, student achievement at the high school level has been flat in recent years,” Duncan said in a statement released Wednesday.

Regionally, a couple of Midwest states stand on the test. Most notable, is South Dakota. Seniors who took the NAEP test there scored higher than the national average in both reading and math. Iowa students scored higher than the national average in reading.

The NAEP test is widely considered one of the best ways for states to compare student performance.