Earlier quoted context omitted.
Right now Wikipedia says: One in four (26%) Iranian researchers is a woman, which is close to the world average (28%). In 2008, half of researchers were employed in academia (51.5%), one-third in the government sector (33.6%) and just under one in seven in the business sector (15.0%). Within the business sector, 22% of researchers were women in 2013, the same proportion as in Ireland, Israel, Italy and Norway. Quotin…
The Forbes article is talking about majors, not practicing researchers.
The most popular in 2013 were social sciences (1.9 million students, of which 1.1 million women) and engineering (1.5 million, of which 373 415 women). Women also made up two-thirds of medical students.
Also, practicing researchers probably would be much better metric than students - if the student graduates as STEM major but then does nothing of the sort, then it's not really so relevant for participation anymore. If we had such situation in US, we would reasonably ask what is preventing those student from entering the labor market and consider situation where the distribution is 70/30 outside of university and 25/75 on the labor market abnormal.