Coeducation at Notre Dame has lessened the cross-highway marital pairings of Saint Mary's and ND students. An analysis by Paul Perl '00Ph.D. shows that the percentage of women in each Saint Mary's graduating class marrying Notre Dame graduates rose fairly steadily from 1950 until around 1972, the advent of coeducation. At that point, more than 1 in 4 Saint Mary's graduates were taking their vows with Notre Dame men. However, that ratio plummeted to about 1 in 10 by the end of the decade and, after leveling off in the 1980s, drifted lower still in the 1990s. Part of the reason may be that there are simply fewer Notre Dame men around to marry than before coeducation. Although total undergraduate enrollment has remained fairly steady since the 1970s (roughly 6,000-8,000), today only about half that number are men. Perl, a research associate with the Center for Applied Research in the Apostolate, a sociological research institute of the Catholic Church affiliated with Georgetown University, also theorizes that grooms are switching to Notre Dame women for brides at the expense of Saint Mary's women. But so far he's been unable to gather the statistical information from Notre Dame's alumni database to verify it.