Duke's regular decision acceptance rate was less than 9 percent for the first time ever this year.

When admissions decisions were released at 7 p.m. Thursday, 2,501 of the 28,600 regular decision applicants—8.7 percent—learned that they were accepted. The University's early decision acceptance rate of 23.5 percent for the Class of 2020 was also its lowest ever, with early decision applicants comprising 48 percent of the class.

An additional 49 students who applied early and were deferred were admitted, down from 69 students last year. Last year's regular decision acceptance rate was 9.4 percent.

Dean of Admissions Christoph Guttentag said that one reason the admissions rate fell further this year was because of last year's exceptionally high regular decision yield rate

"Because the number of students we admitted last year resulted in over enrollment, we admitted fewer students this year on the assumption that the yield will be similar," Guttentag said. "We have admitted 150 students fewer than last year."

Duke's overall acceptance rate for next year's class combining early and regular decision results was 10.4 percent.

Accepted students have until May 1 to make their final decisions, with the University offering Blue Devil Days—two-day events that give students the chance to get familiar with Duke—April 7-8, April 18-19 and April 24-25.

Guttentag noted that admissions officers paid particularly close attention to first-generation students who would make good Washington Duke scholars but said that this year's applicant pool was not significantly different from last year's in its makeup. He added that there was an increased number of applications from students of color.

Although there have been significant events in the past year that could have impacted application numbers—such as last year's men's basketball national championship or recent incidents of discrimination on campus—Guttentag said that he did not think individual events affected students' decisions to apply.

"Students are looking for active campuses where students are engaged," Guttentag said. "I don't think that there are students that would apply and then decide not to apply because of a single event." 

Update: This article was updated Sunday to include Guttentag's comments.