The already slim herd of female CEOs is thinning out.

The number of women CEOs at Fortune 500 companies dropped from 2017 to 2018, scuttling down to 24 from its previous high of 32, per Fortune. In other words, the number of female chief executives dropped by 25% in a single year — and now make up just under 5% of all CEOs.

A string of prominent exits in recent months drove that decrease: Denise Morrison of Campbell Soup Co. abruptly announced her retirement last week amid sinking soup sales. Margo Georgiadis, CEO of Mattel Inc. for just over a year, left the toy brand in April for the company behind Ancestry.com.

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Meanwhile, longtime Hewlett Packard Enterprise CEO Meg Whitman, citing a need for a “deeper technologist” at the helm, stepped down in November; Irene Rosenfeld also left snack-food empire Mondelez International Inc. in November; and Shira Goodman bade farewell to Staples Inc. this year. After Sheri McCoy departed from Avon — which bills itself as “the company for women” — the beauty brand replaced her with its first male chief executive since 1999.

Despite the poor optics, female Fortune 500 CEOs aren’t leaving their companies at higher rates than male ones, according to data from the research firm Equilar — rather, men and women have jumped ship at similar rates since early 2017. Women’s exits may simply be more noticeable since there are fewer of them in the first place, as the Wall Street Journal notes.

“As long as we have these fortuitous (women-CEO) appointments instead of a real gender pipeline being built as a regular course of business, the numbers are going to be volatile,” Jane Stevenson of the executive recruitment firm Korn/Ferry International told the Journal.

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Fortune did, however, add a handful of boss women to the 2018 mix: Kohl’s elevated exec Michelle Gass to its top job; health insurer Anthem tapped industry vet Gail Boudreaux as CEO; and Yum China promoted executive Joey Wat to lead the company. Mary Dillon, Ulta Beauty’s CEO since 2013, joined the ranks after her company made the Fortune 500 list this year.

And Wall Street had its own bright spot earlier this week, as the New York Stock Exchange named chief operating officer Stacey Cunningham as its first female president in its 226-year history.