Market research company finds women are buying more jeans, driving sales growth.

The U.S. sales of men’s and women’s jeans grew 2 percent to nearly $13 billion, showing the category’s first growth in years, according to the NPD Group.

The recent growth in the jeans category was driven by a 4 percent increase in the number of pairs of women’s jeans sold, with nearly 304 million pairs sold in the 12 months ending June 2016.

Furthermore, women’s jeans represent 60 percent of total adult jeans unit sales for the year, according to the NPD Group.

“The denim industry has the opportunity to turn this positive shift in volume into momentum toward significant dollar growth,” says Marshal Cohen, chief industry analyst, NPD Group. “It’s good to see that women are buying more jeans than they were a year ago, but the average spend isn’t growing. The industry needs to embrace this opportunity, which means more innovation and more inventory upfront to help perpetuate the consumer interest.”