University entrance is based largely on the scores that students achieved in entrance examinations (nyūgaku shiken (入学試験?)). Private institutions accounted for nearly 80% of all university enrollments in 1991, but with a few exceptions such as Waseda University and Keio University, the public national universities are more highly regarded. Especially, National Seven Universities are the most prestigious. This distinction had its origins in historical factors—the long years of dominance of the select imperial universities, such as Tokyo and Kyoto universities, which trained Japan's leaders before the war—and also in differences in quality, particularly in facilities and faculty ratios.