The incoming class of graduate students is Princeton’s biggest ever, but the ­graduate school had mixed results in attracting students in underrepresented groups.  

For women in science and engineering, the school reported the highest number of applicants and enrolled students of the past five years, with 97 students accepting Princeton’s offer as the yield rebounded after two down years.

But the number of underrepresented U.S. minorities — African-American, Hispanic, and Native American students — declined for the second straight year, as did the yield. Thirty-three students accepted Princeton’s offer, down from 39 last year and 48 two years ago.

“We’re encouraged by how the pool [of minority students] has grown in numbers and strength,” graduate school Dean William Russel said. “But we’re very disappointed that it is not translating into enrolled students. One factor is that the competition with our peers has increased with the strength of the pool.”