The number of sexual assault reports at the Air Force Academy skyrocketed in the 2014-15 academic year, with 49 cadets reporting attacks, according to a report released Friday by the Pentagon - more than the U.S. Military Academy at West Point, N.Y., and the Naval Academy in Annapolis, Md., combined.
A combined 91 sexual assaults were reported at the three service academies in 2015.
Air Force Academy reports nearly doubled over 2013-14, when 25 attacks were reported.
The academy said the high number of reports shows cadets have confidence in the system.
"The victim is our main priority; in order to provide them the care they need, we must encourage them to come forward and report these crimes," the academy said in a statement. "In doing so, cadets demonstrate their trust and confidence in our program. So much so, each year between 15 and 20 percent of reports are from incidents that occurred prior to the cadet arriving at the Academy."
At West Point, 17 assaults were reported in 2014-15, up from 11 the previous year. The Naval Academy had 25 reports, compared with 23 a year earlier.
The Pentagon said it was encouraged academy cadets felt free to report sexual assaults, one of the nation's most under-reported crimes.
"We are encouraged by the steps the academies have taken to eliminate sexual assault," Maj. Gen. Camille Nichols, who heads Pentagon sexual assault prevention efforts, said in a statement. "All three academies are taking innovative approaches to improve both respect and safety of cadets and midshipmen."
The Air Force Academy this week held an evidence hearing for a cadet charged with sexual assault and has two courts-martial lined up for other sexual assault cases.
"I think it's appropriate for people to feel frustrated about hearing this in the news. Bottom line is that if this were an easy problem, we would have solved it years ago," said Nate Galbreath, the senior executive adviser for the Pentagon's sexual assault prevention office. "Unfortunately, this is a very hard problem to solve."
The three academies had a combined 59 reports in the 2013-14 academic year. Also, sexual harassment complaints rose by 40 percent to a total of 28 during the last school year. The Naval Academy had 13, Air Force eight and West Point seven. School-by-school totals for the previous year weren't released.
At AFA, 22 cadets made "restricted reports" of sexual assault, a move that allows cadets to get counseling and other help but keeps the case out of law enforcement hands. Twenty-seven cadets made unrestricted reports, allowing prosecution.
A concern at the academy is that some victims have been ostracized for reporting the crime.
"Onsite observations and interviews disclosed that social media use is a primary means by which some victims who reported sexual assault have experienced public criticism," the report said.
The Pentagon lauded Air Force efforts to clean up conduct on academy sports teams, saying that no widespread sexual assault issues were noted on teams last year.
"No such team incidents were reported this year; however, attitudes that support such behavior remain an area of concern," the report said.
Pentagon investigators criticized the academy for failing to develop appropriate measures to gauge sexual assault prevention efforts at the school but lauded progress in other efforts, including improved investigations.
The Defense Department in 2015 didn't survey cadets on sexual harassment incidents as they have in past years, instead conducting focus groups on campus.
A report released last year showed that 10 percent of female cadets at Air Force had suffered unwanted sexual contact.
The Pentagon praised Air Force Academy Superintendent Lt. Gen. Michelle Johnson for work to curb sexual violence on the campus.
"The department saw substantive evidence that the superintendent and her leadership team were fully engaged in making sexual assault prevention and response a priority for the Academy," the report said.
The Associated Press contributed to this story.