It's about internalizing the idea that it's a feasible choice you give actual thought to.
How many girls and women fall into each category?
Now that "tech" is so important and lucrative I'm sure this is changing to some extent, but this is a recent trend that's probably 5 years old at most. Tech wasn't viewed the same as it was now in 2012-2014 and felt like a much more risky and inaccessible field. Now it looks a lot more like any other high paying corporate job.
The Dot Net bubble in the 90s was arguably the biggest news story of the decade. Everyone knew there was tons of money to be had in tech, and stories of people landing jobs at startups after learning a little bit of HTML.