As white baby boomers retire and leave the workforce, their replacements are increasingly a different demographic: minority women. A Washington Post analysis of Labor Department data found that “for the first time, most new hires of prime working age (25 to 54) are people of color.”

The analysis showed that there are 5.2 million more Americans with jobs than at the end of 2016; 4.5 million of those employed are minorities and a lot of them are women. They have helped push the U.S workforce over this historic threshold.

From the Washington Post:

Economists say the minority hiring boom is explained mainly by a tight labor market that is forcing employers to look beyond their normal pool of candidates. But interviews with more than 30 new hires, their managers and caseworkers who help people find jobs suggest other forces, such as cultural attitudes and educational attainment, are pushing up the supply of minority women in the work world.

Many Latino families are now pushing young women to further their education and seek employment outside the home, which is a major shift from past generations when they were expected to stay with the kids while the men went to work. Since families now often need two incomes to cover rent and other costs of living, more women have joined the labor market to help bring in more money. Indeed, minority women over age 45 have been earning the most jobs.

The Post also writes that deportation practices may be pushing more women into the workforce, especially since 90 percent of those arrested by ICE are men. “We see women entering the workforce because their husbands may no longer be in the country,” said Samantha Sherman, chief program officer at the Wesley Community Center in Houston.

But as the U.S economy has begun to slow, so has job growth. Politicians and top policymakers have cited the importance of keeping the economy expansion going to allow more Americans to get jobs. The post says “it’s especially critical for many minority families, who usually earn less and have far less wealth than whites.”

“We’ve seen a lot of gains in employment among lower-income and lower-education groups,” said Marianne Wanamaker, an economist and former member of Trump’s Council of Economic Advisers. “But it is precisely those groups that are vulnerable to layoffs if economic activity slows.”