Key points are not available for this paper at this time.
Sandra L. Hofferth, Joan R. Kahn, Wendy Baldwin, Premarital Sexual Activity Among U.S. Teenage Women Over the Past Three Decades, Family Planning Perspectives, Vol. 19, No. 2 (Mar. - Apr., 1987), pp. 46-53
Hofferth et al. (Sun,) studied this question.