What a coworker did when he was starting college back some decades, he asked where all the COBOL jobs were, the teacher got very angry, so he dropped out and went to a different university, where they were teaching Delphi / VB which definitely had a better job market. So you might never have a "perfect" number, but at least locally, you can kind of figure out what local employers are hiring for, which is usually what you'd care most about anyway. I think we've reached a point where unless you're doing something specialized, for the most part programming language choice is about developer familiarity these days.
What do you suggest instead, then?
Not worrying about language rankings.
What a coworker did when he was starting college back some decades, he asked where all the COBOL jobs were, the teacher got very angry, so he dropped out and went to a different university, where they were teaching Delphi / VB which definitely had a better job market. So you might never have a "perfect" number, but at least locally, you can kind of figure out what local employers are hiring for, which is usually what you'd care most about anyway. I think we've reached a point where unless you're doing something specialized, for the most part programming language choice is about developer familiarity these days.