The article links to the actual studies. This is an NPR article! not a scientific thesis.. As far as pop articles go it’s far more well referenced than the average.
For reference, here's one that answers some of what I'm asking:
https://theicct.org/publication/a-global-comparison-of-the-l...
One could even ignore all the text and just look at the bar chart for the numbers.
Any original analysis that’s worth its beans is going to be far denser than that reference or the NPR article. Scientific and technical publications aren’t quite as bad as reading legalese but they’re close, full of jargon and precise language.
Since that short reference with the bar chart was too dense, then what you’re looking for definitely seems to be a pop-sci type summary - like the original NPR article.
I found what I was looking for already. Both the NPR article and the chart were digestable for me. I originally complained the article had no numbers, but you prompted me to read it more closely at which point I found a study with the easy-to-read chart. I posted that study directly in a comment, then "ortusdux" made a snarky comment about needing a simpler article, which I assume was directed at me because I didn't originally find the references in the NPR article.