Military installations in the Washington, D.C., region were typically associated with the lowest risk of sexual assault for men and women.
The findings were published on Friday in a RAND Corporation study, commissioned by the Pentagon, that used data collected in 2014 through more than 170,000 surveys of active duty service members. The study identified the 15 lowest-risk and highest-risk installations for men and women in each service.
Although the data is four years old, the report serves as a snapshot of where service members at that time may have been at the most risk of sexual assault.
In a statement on Friday, the Service Women’s Action Network (SWAN), a nonprofit that advocates for issues related to servicewomen, said military base commanders should welcome the data as a valuable tool to measure the success or failure of their efforts to prevent sexual harassment and assault at their installations.
"SWAN hopes that base commanders at all installations, but especially the highest risk installations, will examine the data and realize that any sexual assault reported at their base represents fratricide within their ranks and a failure in their duty to protect those who serve under them," said retired Col. Ellen Haring, acting SWAN CEO.
Of the 15 highest-risk Naval installations for women, 13 were ships or clusters of ships, including eight of the ten aircraft carriers, RAND found. There are typically about 5,000 sailors aboard a carrier.
"Our model estimates that more than 10 percent of all women experienced a sexual assault at each of these high-risk installations over a one-year period, and more than 15 percent of all women were assaulted at two of them," the study said.
Those two installations where the risk of sexual assault was over 15 percent were Naval Support Activity (NSA) Charleston (South Carolina) and the USS George Washington aircraft carrier.
Ships and clusters of ships also proved to be the highest-risk locations for men, though the percentage was much lower at between 2 and 4 percent.
However, on at least one ship, RAND estimated that close to one in every 25 male sailors was sexually assaulted and "more than 2.5 percent of men were assaulted on all of the ships in the highest-risk list."
There were no ships among the lowest-risk installations for male or female sailors.
Female airmen were at the lowest risk of sexual assault compared to the other services with even the highest-risk installations estimated at less than 5 percent.
"The five highest-risk bases for Air Force women are all Air Education and Training Command bases, with the top three focused on undergraduate pilot training," the study said.
The top three highest-risk installations for female airmen were Vance (Oklahoma), Laughlin (Texas), and Altus (Oklahoma).
For male airmen, the highest-risk installations estimated a sexual assault risk at about 0.5 percent and also included Atlus and Laughlin.
Female soldiers were found to be at the highest risk of sexual assault (between 5 and 10 percent) at large Army installations in the U.S., Japan, and South Korea, as well as two large training programs (Fort Huachuca in Arizona and the Presidio of Monterey in California).
Among the U.S. bases that posed the highest risk to women were Fort Drum (New York), Fort Riley (Kansas), and Fort Carson (Colorado). The lowest-risk installations included two Air Force bases with populations of Army soldiers and two medical centers.
For male soldiers, some of the highest-risk installations (between 1 and 2 percent) were located overseas, including in Italy, Germany, and South Korea.
As the Marine Corps is a much smaller service, RAND only ranked the five lowest- and highest-risk installations, instead of 15.
Female Marines faced a roughly 10 percent risk of sexual assault at the highest-risk installations, which included Air Station Yuma (Arizona), Air Ground Combat Center Twentynine Palms (California), and Air Station Beaufort (South Carolina).
The lowest-risk installations for women ranked between 5 and 8 percent and included Combat Development Command Quantico (Virginia) and the Mobile 3rd Marine Expeditionary Unit (Japan).
Male Marines were at the highest risk of sexual assault (between 1 and 2 percent) at bases in Japan and South Korea, and at the lowest risk in the Pentagon and Camp H. M. Smith (Hawaii).