The overall divorce rate among both male and female service members held steady in fiscal 2017, marking the fourth year running that the rate has hovered between 3 percent and 3.1 percent.

About 21,290 of 689,060 married troops divorced over the course of fiscal 2017, according to data released Tuesday by the Pentagon to Military.com.

In 2016, the rate was slightly higher, with about 22,500 divorces out of 707,230 marriages, according to historic data compiled by Military.com.

The military divorce rate is calculated by comparing the number of troops listed as married in the Pentagon's personnel system at the beginning of the fiscal year with the number who report divorces over the year. The information is managed and compiled by the Defense Manpower Data Center.

Hidden in that larger statistic is a breakout by branch, paygrade and gender that tells an interesting story about the struggles of military marriages, said Benjamin Karney, a researcher with Rand Corp. who has long tracked the military divorce rate.

Although divorce rates among female troops continue to be much higher overall than their male counterparts -- by about 275 percent in the Army, for example -- the rates among men across the services and women in the Army and Air Force have continued a steady decline, while women in the Navy fluctuated slightly.

But female Marines continue to struggle to hold their marriages together, with a divorce rate of 7.1 percent that has increased or held steady annually since 2012. That rate saw its high-water mark in 2010, when it sat at about 9.9 percent.

That the rate isn't declining could be a sign that family policies in the Marine Corps are not friendly toward married women, Karney said.

"When you see these changes, what's driving it is almost never changes in values or couples' abilities to talk effectively to each other," he said. "What is changing it is military policy."

The divorce rate among military personnel and the total U.S. divorce rate cannot be easily compared because they are not measured the same way.

The total U.S. divorce rate, which is measured per 1,000 residents and does not factor in six states including California, sat at 3.2 percent in 2016, the latest year for which information is available.

Although the overall divorce rate hasn't changed dramatically, the rate of marriage in the military has seen a steady decline, according to Defense Department data compiled by Military.com.

In fiscal 2017, about 51.7 percent of all active-duty troops were married, compared to 56.6 percent in 2011.

That change, Karney said, reflects a similar marriage trend in the civilian world, where about 49 percent of U.S. adults are currently married, according to the Centers for Disease Control.

"It's not a surprise that it's also affecting military life," he said.

Military members typically marry in higher rates than civilians thanks to benefits such as housing allowances and housing available only to married personnel.

Another factor that could be contributing to the declining marriage rate might be an attitude among members of the millennial generation, born between about 1982 and 1997, that they don't need the traditional support systems that come with military marriage, said Corie Weathers, a licensed professional counselor and Military.com marriage columnist.

"They see their purpose as not necessarily family, because family isn't big enough to them," she said. "They want to be out there making a difference and making change outside of the typical military world."

-- Amy Bushatz can be reached at amy.bushatz@military.com.