According to the link above, there were approximately equal amounts of 24-year-old men and women getting bachelor's degrees in 1980, but undergraduating men proportionally outnumbered women in natural sciences and engineering 2.66:1. By 1998, bachelor's degrees had increased by 34% for men and 85% for women, but in NS&E the increases had been 23% and 110%, leaving the proportional gender ratio of NS&E undergraduates at 2.14:1. Notably, engineering degrees for men fell by 21%, which had a larger impact than women entering.

I didn't hunt for post-bubble figures.