More than 1 million fewer students are enrolled in college now than before the pandemic began. According to new data released Thursday, U.S. colleges and universities saw a drop of nearly 500,000 undergraduate students in the fall of 2021, continuing a historic decline that began the previous fall.

“It’s very frightening,” says Doug Shapiro, who leads the research center at the National Student Clearinghouse, where the new data comes from. “Far from filling the hole of [2020’s] enrollment declines, we are still digging it deeper.”

Compared with the fall of 2019, the last fall semester before the coronavirus pandemic, undergraduate enrollment has fallen a total of 6.6%. That represents the largest two-year decrease in more than 50 years, Shapiro says.

The nation’s community colleges are continuing to feel the bulk of the decline, with a 13% enrollment drop over the course of the pandemic. But the fall 2021 numbers show that bachelor’s degree-seeking students at four-year colleges are making up about half of the shrinkage in undergraduate students, a big shift from the fall of 2020, when the vast majority of the declines were among associate degree seekers.

“The phenomenon of students sitting out of college seems to be more widespread. It’s not just the community colleges anymore,” says Shapiro. “That could be the beginning of a whole generation of students rethinking the value of college itself. I think if that were the case, this is much more serious than just a temporary pandemic-related disruption.”