Over the past decade, there has been a sense in the art world that gender equity was on the horizon: Emerging female artists were landing high-profile solo shows, museums were staging women-themed exhibitions, grants were being awarded to boost female artists, and long-neglected artists were being given overdue recognition.

This assumption of progress is being sharply challenged by new data showing that between 2008 and 2018, only 11 percent of art acquired by the country’s top museums for their permanent collections was by women. And contrary to any hope that acquisitions of artworks by women are inching upward, the percentage remained relatively stagnant, according to the data, released on Thursday.

The new analysis was by Artnet, an art market information company, and “In Other Words,” a weekly podcast and newsletter produced by Art Agency, Partners, an art advisory firm that was acquired by Sotheby’s.

“The perception of change was more than the reality,” said Julia Halperin, the executive editor of Artnet News and one of two lead authors on the report. “The shows for women were getting more attention, but the numbers actually weren’t changing.”