(NewsNation) — Female professors at Vassar College in New York are suing the school over allegations that the college has been paying women less than men for the past two decades.

The lawsuit filed in federal court in late August alleges that Vassar, the historic women’s college, has “systematically” delayed promotions for women, offered men higher starting salaries and unfairly evaluated female professors.

The suit cites data provided by the college to the Chronicle of Higher Education that shows a pay gap of as much as 14.6% in the 2019-2020 school year, when the average salary for women was $135,435, compared to $155,233 for men. The gap has grown since 2003-2004, when it was 7.6%.

In the most recent data year of 2021-2022, the pay gap between men and women was 10%, with female professors making $139,322 compared to $153,238 for men, according to the lawsuit.

“There is no doubt that Vassar has long known about — and long failed to correct — this pay disparity,” lawyers for the professors wrote. The lawsuit was filed on behalf of Wendy Graham, Maria Höhn, Mia Mask, Cindy Schwarz and Debra Zeifman.

The lawsuit alleges that female professors tried for years to rectify the pay gap, only to be rebuffed by the administration.

Lawyers cite a 2011 faculty retreat hosted by then-Dean of Faculty Jon Chenette, wherein a presentation on the pay disparity was discussed among participants.

Two years later, the lawsuit alleges, a group of women approached administration hoping to redress the pay disparities apparent in the Chronicle data.

“In an email dated September 30, 2013, then-Acting Dean of Faculty Stephen Rock wrote: ‘I am sorry to say that the raw data will not be released.’ Though Vassar had already disclosed the requested data to a male member of the faculty, Dean Rock explained it was because this man was a ‘world-class econometrician,'” the lawsuit states. “Among the women faculty with whom Dean Rock refused to share the raw data were: a world-class economist, a world-class physicist, a world-class psychologist, a world-class biologist, and two world-class historians.”

Vassar is a private liberal arts college in Poughkeepsie, New York, and one the historic Seven Sisters, the first women’s colleges in the United States. It was founded in 1861 “to offer women a fully equivalent education to that of the best men’s colleges of the period,” and later opened its its doors to men in 1969.

Unlike public universities, private institutions are not required to disclose their salary data, which the plaintiffs take issue with.

The lawsuit states: “Since at least as early as 2008, and consistently since then, female professors have internally elevated concerns to the Vassar administration about unequal pay within the College’s ranks. Instead of remedying its gender pay gap, Vassar responded by decreasing the level of transparency about faculty salaries, in an apparent attempt to mask its decades-long pattern of underpaying of women.”

In a letter to the editor published in the student newspaper last month, President Elizabeth Bradley said the plaintiffs “have a different understanding of the relevant facts and law that is at issue in this dispute.”

Annual faculty salary increases are guided by a faculty-led peer-review process as described in Vassar’s Governance and the Faculty Handbook,” Bradley wrote.

The lawsuit seeks class-action status on behalf of all full female professors since May 14, 2015, and asks for backpay in wages as well as punitive damages.