Despite ongoing efforts to combat sexual violence in the military, sexual assault rates among service members have spiked since 2016.

The Pentagon’s biennial report on sexual assault in the military, released on Thursday, shows a 38 percent rise in military sexual assaults between 2016 and 2018. The report, which anonymously surveyed over 100,000 service members from the Army, Navy, Marines and Air Force, is conducted once every two years to estimate the rate of sexual violence in the military.

The survey found 20,500 instances of “unwanted sexual contact,” which includes actions like groping, sexual assault and rape ― an increase from the 2016 report, which found 14,900 instances of unwanted sexual contact. More than 85 percent of survivors knew their perpetrator, and alcohol was involved in 62 percent of all assaults.

“To put it bluntly, we are not performing to the standards and expectations we have for ourselves or for each other. This is unacceptable,” acting Defense Secretary Pat Shanahan wrote in a memo Thursday morning. “We cannot shrink from facing the challenge head on. We must, and will, do better.”

The service members with the highest risk of being assaulted are enlisted women between the ages of 17 and 24.

About 1 in 3 service members who reported an incident of sexual assault reported it to the Department of Defense, which is roughly the same reporting rate as in 2016. As the DOD points out, the reporting rate in 2018 is quadruple the rate it was 10 years ago. Of those who reported, however, 64 percent said they had negative experiences or “retaliation” associated with coming forward.

Sen. Martha McSally (R-Ariz.), who revealed in March that she was raped by a superior officer while serving in the Air Force, told reporters on a Thursday call that although the Pentagon’s suggestions for future improvement are good, the “work is not done.”

“They are doing the best they can, but they are under-resourced and under-manned, and so I believe this is a readiness issue,” she said. “Just like when we have other readiness issues where we need bombs and bullets and training hours, we need to invest more resources into this process to make sure we’re addressing the shortfalls we’ve seen throughout the different bases I’ve visited.”

Navy Rear Adm. Ann Burkhardt, the director of the Department of Defense’s Sexual Assault Prevention and Response Office, said the sharp increase in reported sexual assaults in the military is due to leadership.

“We can’t be deterred when we see rates that we see that we can’t sustain,” she continued. “Our progress over the decade is we have seen the prevalence of sexual assault decrease, but what we have learned from this year’s report is this is a situation that can bounce back, and we have to then be deliberate and kind of confirmed in our resolution to take action.”

Read the report below: