Enrollments at colleges and universities dropped for the eighth semester in a row this fall, down nearly 2 percent below what they were last fall, new figures show.

The Topic: College enrollment is down 6 percent in the last four years.Why It Matters: The trend threatens degree-completion goals.

The number of students over 24 continued to decline sharply—more than 4 percent—according to the National Student Clearinghouse Research Center, which tracks this. Enrollment at four-year for-profit institutions plunged by nearly 14 percent.

Four-year public universities and colleges saw an incremental increase in their number of students, up by less than half of 1 percent. Enrollments at private nonprofit institutions fell by more than 3 percent among part-time students, and by a total of three-tenths of 1 percent.*

“This fall’s numbers show ongoing challenges for colleges and universities,” said Doug Shapiro, the research center’s executive director. “Adult students are still leaving higher education in large numbers, particularly for-profit institutions and community colleges.”

In all, U.S. university and college enrollment has fallen 6 percent in the last four years, even as policymakers push to increase the proportion of the population with degrees.

*Clarification: An earlier version of this story noted that enrollments at private, nonprofit institutions fell by more than 3 percent. That figure reflected a drop in part-time enrollment. Total enrollment fell by three-tenths of 1 percent.