But 4.3 percent of the United States' active-duty women still say they were the victims of unwanted sexual contact in the last year, and most still aren't reporting those assaults. Some of those who did report their assaults faced retaliation, according to the Pentagon's findings.
In the 136-page report due to be publicly released Thursday, the Pentagon said more victims are reporting sexual assaults. In 2012, just 1-in-10 victims reported those assaults, and by 2014, 1-in-4 did. The report pointed to a 50 percent increase in the number of victims who reported the assaults from 2012 to 2013, and another 8 percent leap in 2014.
The Pentagon said, "The importance of this upward trend in reporting cannot be overstated."
"Increased reporting signals not only growing trust of command and confidence in the response system, but serves as the gateway to provide more victims with support and to hold a greater number of offenders appropriately accountable," the report said.
Defense Secretary Chuck Hagel, Joint Chiefs Chairman Gen. Martin Dempsey and Gen. Jeffrey Snow, the director of the Pentagon's Sexual Assault Prevention and Response Office, delivered the report to the White House on Tuesday.
The report noted a major increase in reports of sexual assaults in recent years -- from 3,604 in 2012 to 5,518 in 2013 and then 5,983 in 2014 -- and said it's "unlikely" the bump is happening because more crimes are taking place.
"Given the underreported nature of sexual assault, the department believes this increase in reporting is likely due to greater victim confidence in the response system," the report said.
The number of active-duty women who said they were victims of unwanted sexual contact in the last year was 4.3 percent in 2014 -- down from 6.1 percent in 2012 -- the report said, citing surveys from those two years.
Victims of sexual assault can file "restricted" reports, which allows them to access health services without launching investigations and legal proceedings, or "unrestricted" reports, which do trigger independent investigations. In 2014, the Pentagon said, 19 percent of the victims who filed restricted reports later decided to make those reports unrestricted and pursue investigations -- the highest figure it has ever recorded.
The report also included a survey of more than 150 military sexual assault survivors. It found that three-quarters said they'd recommend that others report being assaulted -- and 90 percent said they were satisfied with the aid and legal counsel they received.
"However, too many of these respondents indicated they perceived social and/or professional retaliation as a result of making a report," the Pentagon said.
That admission comes as lawmakers push for bigger changes to separate sexual assault prosecutions and court-martial proceedings from the military's chain of command.
New York Democratic Sen. Kirsten Gillibrand is making a new push for that legislation. She's seeking to have the proposal added into a defense spending authorization bill that's set for a House vote in the coming days.
"The military has not been able to demonstrate that they have made a difference and they need to be held to the scrutiny and that standard this year because throughout the last year we have continued to see evidence of how much farther we have to go to solve sexual assault in the military," Gillibrand said Tuesday at a news conference with a bipartisan set of senators who are advocating for her proposal.
Among the GOP proponents is Sen. Rand Paul, the Kentucky Republican and likely 2016 presidential contender.
"If you were in a corporation you would not report to your boss -- you would go to the police," he said. "In the military it's a little different but you still wouldn't want to go to your boss directly or you wouldn't want your boss to be making the decisions -- particularly if your boss was buddies with the perpetrator -- you would want people you don't know outside the chain of command."