After a banner year in 2012 for women getting elected to Congress, the number of female members of the House and Senate stands at an all-time high.

Photo caption: A mere five out of 50 are female: Republicans Nikki Haley of South Carolina, Jan Brewer of Arizona, Susana Martinez of New Mexico and Mary Fallin of Oklahoma, and Democrat Maggie Hassan of New Hampshire.

“I do think that the challenges of running for a chief executive position … are significant,” Hassan, who is in Washington this weekend for a National Governors Association meeting, told POLITICO.

Some experts attribute the disparity to age-old hurdles that women face reaching the top rungs of the workplace: the difficulty juggling career and family, and the higher bar women have to clear to be seen as competent executives.

But advocates for women in politics say it’s past time for the ranks of female governors to grow. They’ll have a chance to make headway next year, when a large number of governor’s seats will be up for grabs.

(Battered GOP govs change tune ahead of 2014)

“The fact that we only have five women in governorships reveals the true state of play for women in electoral politics in this country,” said Sam Bennett, president of She Should Run, an organization that encourages and supports female candidates. “Women have to overcome barriers men never even have to think about.”

The most female governors who have ever been in office at once is nine, in both 2004 and 2007. By comparison, Congress now has 98 female members: 20 in the Senate and 78 in the House, both historic highs. Sixteen of the 20 women senators are Democrats, whereas four of the five current female governors are Republicans.

EMILY’s List President Stephanie Schriock pointed out that the number of female Democratic governors was diminished when North Carolina Gov. Bev Perdue chose not to run again, Washington Gov. Christine Gregoire was term-limited, and President Obama tapped Janet Napolitano and Kathleen Sebelius for his cabinet.

“It’s an interesting dilemma: President Obama took two of our best [female] governors and made them cabinet secretaries,” she said.

Despite the dearth of female state executives now, the numbers are a lot higher than they used to be. And given the strides women have made in politics, it’s surprising that the first woman elected as governor of a state in her own right (as opposed to replacing her husband) was less than 40 years ago.

Ella Grasso, who was elected governor of Connecticut in 1975, is one of only 35 female governors ever – compared with more than 2,000 male governors throughout the nation’s history. Just 23 of the 35 were elected in their own right; the others took over after their husbands were unable to serve or, like Brewer, came into the position through constitutional succession.