Student performance on the SAT college entrance exam is lagging, continuing a mostly downward trend over the last five years.

The College Board says in a report that a record number of students took the exam.

The nonprofit organization, which administers the exam, said in a report released Thursday that the mean score in reading was 495, down from 497 the previous year. For math, it was 511, down from 513. Writing scores dropped three points, to 484 from 487. The top score in each category is 800.

The latest scores continue a decline since 2010, when the means were 500 in reading, 515 in math, and 491 in writing.

A record 1.7 million students from the Class of 2015 took the exam, up from 1.67 million in the 2014 class.

The College Board says about 42 percent of test-takers, more than 712,000 students, met a benchmark that indicates they're likely ready for college-level work or career-training programs. The benchmark is a combined score of 1550 or higher for math, reading and writing. The percentage meeting that benchmark has largely remained the same in the last few years.

About 16 percent of African-Americans met that benchmark; 61 percent of Asian test-takers hit it, followed by about 53 percent of white test-takers, 33 percent of Native Americans and 23 percent of Hispanics.

"We know we can, and need, to do better," says Cyndie Schmeiser, chief of assessment for the Board. "Simply doing the same things we have been doing is not going to improve these numbers."

The SAT exam is undergoing a major revamp that will roll out next year. The idea behind the update is to make the exam more representative of what students study in high school and the skills they need to succeed in college and afterward. The redesign will focus more on areas of math that matter most for college and career readiness, shift away from obscure vocabulary words, and eliminate the guessing penalty.

The College Board is also teaming up with online educator Khan Academy to offer free SAT practice to all students through diagnostic quizzes and interactive practice tests. They will be accessible to anyone with Internet access.

The report said there's also been an increase in the number of students taking the Advanced Placement, or AP, exams and PSAT/NMSQT exam. Passing an AP exam can earn test-takers college credit. The PSAT/NMSQT test is sometimes viewed as a precursor to the SAT. It is used to assess student performance and as a qualifier for National Merit Scholarships.

About 3.8 million students took the PSAT/NMSQT test in the fall of 2014. AP exams were taken by about 2.5 million students in 2015.

More than 1.5 million students received a score of 3 or higher on an AP exam in 2015, up slightly from the previous year.

Depending on the school and the state, college credit may be awarded for scores of 3, 4 or 5 on the AP exams.