The Census Bureau reports that there were as many women as men enrolled in institutions of higher learning in 1980 and 1981. These figures represent a sharp change from historic patterns. As recently as 1965, only 38 percent of college students were women; in 1981, 50 percent were. What that means is that your average girl is just as likely as your average boy to go to college some day --and maybe more so.

But not necessarily at the same time. The same Census Bureau study shows that undergraduate enrollment among those 21 and under increased by about 300,000 students between 1975 and 1981. Enrollment of undergraduates between 22 and 35-- those beyond the age when the student who went straight through school would have graduated-- increased by 648,000. There were 1.6 million undergraduates over 21 in 1970, 2.6 million in 1975, and nearly 3.3 million by 1981.

One reason for this is that the number of Americans age 18-21 peaked in the late 1970s. And the number able to handle college-level work may have declined even more, to judge from the long-term decline in test scores. Colleges and universities, like most institutions, don't voluntarily contract in size, and so they have been looking for new students where they can find them. One obvious source is young people slightly older than traditional college age, who for whatever reasons did not finish college. It appears that a disproportionate number of these people are women. A larger percentage of women than men, it should be added, are part-time students.

This trend could not have occurred--nor would there have been the significant rise in black college students that occurred in 1973-76 and the significant rise in Spanish-origin college students that occurred in 1978-81--without the vast expansion of higher education and especially public higher education that occurred in the 1970s. Enrollment in all colleges and universities increased from 5.7 million in 1965 to 10.7 million in 1981, most of it in public institutions. These are useful numbers to keep in mind the next time someone says that the large sums of public monies spent on higher education have not bought anything. For many young people they have bought opportunities that their parents never anticipated.