For decades, many groups have highlighted the pay disparities between men and women, and a new report from the American Association of University Women pointed out just how big the earnings gap is.

In 2010, American women on average earned just over three-quarters of what men did — women’s annual median earnings were $36,931, compared with $47,715 for men.

In some states, the difference wasn’t as significant. In Washington, DC, for example, full-time working women earned 91 percent of what men earned, while in Vermont and California, women’s pay was 84 percent of what their male counterparts took home.

The worst states were Wyoming and Louisiana, where women earned 64 percent and 67 percent of what men did, respectively.

Dana Schultz, Wisconsin state director of the 9to5 women’s advocacy group, said women are often over-represented in undervalued, underpaid occupations. And since a third of working women are their family’s breadwinner, it’s important not to deny them the “fairness they deserve.”

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