In the latest National Assessment of Educational Progress scores, also known as the “Nation’s Report Card,” it was found that an estimated 37% of U.S high school seniors were adequately prepared for college-level coursework in both subjects. That’s down from the last assessment in 2013, when around 39% of 12th-graders were measured at college-level maths, and 38% at reading.

“Too many 12th-graders are unprepared for the world after high school,” Governing Board member Mitchell Chester said in a statement.

The challenge comes at the tier that ranks students’ proficiency at both subjects as “Below Basic.” When it came to math, 38% fell into this group last year, compared with 35% in 2013. In reading, 28% of students were at this level, compared with 25% two years earlier.

“The students at the top of the distribution are going up and the students at the bottom of the distribution are going down,” Peggy Carr, acting commissioner of the National Center for Education Statistics, told The Wall Street Journal. “There is a widening of the gap between higher and lower-ability students.”

The stagnating test scores for maths and reading among students has been problematic—last October, the Nation’s Report Card found that the mathematical skills of Grade 4 and 8 students in the U.S. dropped for the first time since 1990. Some have had issues with the NAEP’s testing, as it was discovered then that some questions deviated from the Common Core guidelines adopted in around 45 states.