Acting Defense Secretary Patrick Shanahan called for sweeping changes in the way the military handles sexual assaults and harassment as the Pentagon releases a new report showing the problem is getting worse.

“To put it bluntly, we are not performing to the standards and expectations we have for ourselves or for each other,” Shanahan wrote in a memo to top agency officials Wednesday, which the Pentagon released Thursday. “This is unacceptable.”

The biennial report surveyed Army, Navy, Air Force and Marine personnel in 2018. Based on the survey, there were an estimated 20,500 instances of sexual assault, nearly a 40% increase over the 14,900 estimated in 2016. Unwanted sexual contact ranges from groping to rape.

FILE - The Pentagon building is seen in Washington.
FILE – The Pentagon building is seen in Washington.

Enlisted females between the ages of 17 and 24 were at the highest risk of being assaulted, the survey said.

“This report is disheartening, and it personally makes me angry,” Nathan Galbreath, the deputy director of the Sexual Assault Prevention and Response Office, told reporters at the Pentagon on Thursday.

In a memo, Shanahan said sexual harassment should be considered a stand-alone crime in the military, and he recommended launching a program to catch serial offenders in addition to sexual harassment training for junior officers and enlisted leaders.

Elise Van Winkle, the executive director of the Office of Force Resiliency, said the results were “not acceptable by any standard.”

The Marine Corps had the highest prevalence rate for sexual assaults of women at 10.7%. Pentagon officials explained that while the Marine Corps has the fewest women in the military, nearly two-thirds of those female Marines are 17 to 25 years old — the ages considered to be high-risk for sexual assaults.

The Air Force had the lowest estimated rate at 4%.

Male service members who were victims of sexual assault remained at less than 1% in 2018.

Democratic presidential candidate Sen. Kirsten Gillibrand, D-N.Y., speaks at
Democratic presidential candidate Sen. Kirsten Gillibrand, D-N.Y., speaks at a campaign meet-and-greet in Clawson, Mich., March 18, 2019.

The problem has been a major focus for lawmakers, including Democratic Sen. Kirsten Gillibrand of New York, who has made military sexual assault a key issue in her presidential campaign. Republican Sen. Martha McSally of Arizona called for attention to the problem recently when she disclosed that she had been raped while she was in the Air Force.

“The numbers released today confirm that the time is now to impart lasting change within the military and that it is more urgent than ever,” McSally said in a statement.

Overall, the rates of sexual assault in the military have trended downward since 2006, when over 34,000 service members reported some type of sexual assault, but the numbers have fluctuated up and down since then.