Women in state legislatures, over time. (Simon Garnier, graphzoo.tumblr.com , using CAWP data)

South Carolina’s Senate is the nation’s least gender-diverse legislative chamber, with just 2 percent representation, according to data from the Center for American Women and Politics at Rutgers University’s Eagleton Institute of Politics. Of the 45 members (one seat is vacant), just one — Sen. Katrina Frye Shealy (R) — is a woman.

The South Carolina Senate is an extreme example, but no state can claim gender parity in its state legislature or any of its chambers. The closest are the House chambers in Colorado and Vermont or the Senate in Arizona, with women making up 43 percent of each body.

Nationally, women make up just under 1 in 4 state legislators, according to the CAWP data from May and even fewer are in leadership positions.

Of the 335 state legislative leaders, just 60 — 17.9 percent — are women. There are 10 female Senate presidents and six female House speakers. But, compared to the past, women are doing relatively well. Just 27 women have ever been Senate presidents, and only 35 have ever been state House speakers. The nation’s first female state Senate president was New Hampshire’s Vesta Roy (R), who served in the early 1980s, and the first female House speaker was North Dakota’s Minnie Davenport Craig (R), who served in 1933, according to CAWP.

Women today hold the most leadership positions in Oregon (62.5 percent), California (57.1 percent) and Colorado (50 percent). No women are in legislative leadership positions in 16 states.

(Note: Because Nebraska has a unicameral legislature, we only include it in comparisons of total legislative diversity.)

24 states have never had a female governor

Women governors. (Center for American Women and Politics)

Just five states currently have female governors, while 24 have never seen one.

Vermont and Colorado have the most gender diversity in their state legislatures

(Darker shading represents more gender diversity.)

The state legislatures of Colorado and Vermont are the most gender diverse, with 41 percent of each comprised of women. Louisiana, Oklahoma and South Carolina are the least diverse, 13 percent.

The legislatures in Louisiana and South Carolina look least like their state populations

(Darker shading represents more gender diversity.)

The share of women in the legislatures of Louisiana and South Carolina are 38 percentage points below the share of women in the state, making the two the least representative legislatures by gender in the nation. Colorado’s is closest, with female representation in the legislature just nine points shy of their share of the population. Vermont is next, with a 10-point gap.

Arizona has the most gender-diverse Senate

(Darker shading represents more gender diversity.)

Women account for more than 1 in 3 senators in just five states: Arizona, New Hampshire, Colorado, Washington and Minnesota. They account for fewer than 1 in 10 in four states: Oklahoma, Wyoming, West Virginia and South Carolina.

Louisiana has the least gender-diverse House/Assembly

(Darker shading represents more gender diversity.)

Women make up 15 percent or fewer House/Assembly members in Louisiana, Alabama and Tennessee. They make up the most in Colorado and Vermont, with 43 percent of each chamber comprised by women.

The female share of each state legislative body