Imagine the entire city of Dallas was enrolled in college in 2011 — and isn’t anymore. That’s been the effect of a 1.3 million student drop in higher education enrollment since the nation hit an attendance record in the fall of 2011.

Very little has changed, however, for more traditional segments of the college-attending population — four-year public university enrollment and private non-profit college attendance have generally been maintained or even slightly increased each year over that time. The big dips, according to a report from the National Student Clearinghouse Research Center, have been seen at four-year for-profit and community college institutions, while across all educational sectors losses have been felt most heavily when it comes to older students. Those over the age of 24 account for more than 80 percent of the overall decline.

Of course, for-profit schools and community colleges also tend to serve more out-of-work adults — who, as the Wall Street Journal’s Melissa Korn reports, tend to be older and “flocked to colleges during the recession,” but are now finding better employment opportunities, and thus “hitting pause on their higher education pursuits.”

This news is a mixed bag for those implementing Workforce Innovation and Opportunity Act programs. On the one hand, stronger employment among this segment of Americans means WIOA initiatives can be more acutely focused on education and skills training for those still struggling to find jobs, and thus most at need of the assistance. On the other hand, the long-term need for occupational training is still present among those who can find work in a good economy but struggle in a bad one — and will be apparent once again among this population when the economy next falters.

As states get WIOA-sponsored programs underway over the next few years, the challenge will be to ensure that programs that see success — and thus gain momentum — are nimble enough to serve not just those who struggle to find jobs in any economy, but those who are currently employed but might not be when the inevitable economic doldrums return.