This number has been shown to illustrate how these jobs were distributed before and after the advent of the internet and household computers. Here are a couple excerpts from a great piece on this ‘how did it happen’ topic:
“According to the National Center for Education Statistics, in the 1984–1985 academic year women accounted for nearly 37% of all computer science undergraduate students. This number steadily dropped as the widespread use of home computers became more common. A 1985 report on the everyday usage of personal computers within the home found that men were both far more likely to use a computer, and to use it for more hours per week than women. Only 27% of men reported not using a computer on a weekly basis, compared to 55% of females surveyed. As of 2010–2011, women made up just 17.6% of computer science students.
“The central conclusion is that the first personal computers were essentially early gaming systems that firmly catered to males. While early word processing tools were also available, the marketing narrative told the story of a new device that met the needs of men. As more males began purchasing computers for personal use, the “nerdy programmer” classification began to take hold in the professional world of computer science. By the mid-nineties, the percentage of women studying computer science at the postsecondary level had fallen to 28%.”