PHILADELPHIA (AP) — A report released through the University of Pennsylvania’s Graduate School of Education shows that most of the schools in the NCAA’s six major sports conferences have weak graduation rates for African-American male student-athletes.

The Center for the Study of Race and Equity in Education provided data from a four-year study of athletes from the schools that comprise the ACC, Big East, Big Ten, Big 12, Pac 12 and SEC. The findings show that on average, 50.2 percent of African-American male student-athletes graduated within six years and that 96.1 percent of the schools graduated African-American male student-athletes at rates lower than student-athletes overall.

Northwestern of the Big Ten led the way with a graduation rate of 83 percent for its African-American male student-athletes, well above the average undergraduate rate for all schools studied, regardless of race: 72.8 percent. Notre Dame ranked second (81 percent), followed by Villanova and Penn State (78 percent each).

The Penn study refutes an NCAA claim that African-American male student-athletes are 10 percent more likely to graduate than their same-race male peers who are not members of intercollegiate sports teams. The study said that was not true across the six conferences.

“While the graduation disparities were not surprising, what was surprising was the astounding pervasiveness and depth of the disparities, as well as the fact that institutional leaders, the NCAA and athletics conference commissioners have not done more in response to them,” said Shaun R. Harper, the report’s lead author. “Research has yielded clear strategies for (African-American) male student-athlete success. However, there needs to be the institutional will to implement these simple, and often low-cost, solutions, as well as accountability from the media and the athletes themselves.”

Topping the list of the 10 universities with the lowest African-American male student-athlete graduation rates was Iowa State with 30 percent. South Florida, Arizona and Arkansas were close behind at 31 percent.

Overall, the study said 22 universities graduated their African-American male student-athletes at a rate higher than their African-American male undergraduate populations. Kansas State topped the list with a 21 percent higher graduation rate.

The Penn report also addresses universities that have a wildly disproportionate number of African-American male student-athletes. At Marquette, they were over-represented by 77 percent.

The NCAA said in a statement Monday that several academic reforms and other actions the organization has taken already address many of the recommendations in the report. Postseason eligibility is now tied directly to academic success, and new initial eligibility standards are designed to better prepare incoming student-athletes to be successful in college.

“While we’ve seen improvement with academics for minority student-athletes … we are not satisfied and continue to address these challenges as a higher education association,” the NCAA said in the statement.

The NCAA said a number of programs and funding also are offered to help student-athletes be successful, such as the Student Assistance Fund and funding for limited-resource institutions to strengthen academic support.

“We appreciate the report’s authors noting that relatively few student-athletes go pro,” the NCAA said. “That is why student-athletes need to take advantage of their scholarships and stay in school and earn their degrees.”