It did rise most sharply in CS because it was open to women early on when women joined the labor market (previously either holding non-degree jobs or being stay

It did rise most sharply in CS because it was open to women early on when women joined the labor market (previously either holding non-degree jobs or being stay-at-home wives). Once other fields opened up too they left CS for those fields which aligned more with their interests. Maybe there might be two effects at work here: Women joining a field early that was seen as a female job (computer secretaries) that did not align with their interests while conversely men started to join more when the job became more stereotyped as a "male activity" while at the same time being aligned with their interest. Contrast the business curve which also saw an early increase but also is more of a people-interest thing, thus did not see a decline.