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My answer - I think a very large proportion of students have popped their cherries long before the first year of undergrad so I wouldn't say it was a 'tradition', no. 30 years ago: maybe.
"The average age at first intercourse has fallen from 17 to 16 for both men and women.(2)
Nearly a third (30 per cent) of men and a quarter (26 per cent) of women aged 16–19 first had sexual intercourse before the age of 16."