The original article is comparing "a 2023 study showing that only 16% of Americans read for pleasure in a given day, down from the (already low) number of 28% in 2004" with "the percentage of the overall Spanish population that reads for pleasure has increased every year since 2017, reaching 66% in 2025".

I think a big part of the discrepancy probably comes from the different time frames. If you ask somebody who reads for pleasure once a week whether they did so on a given day, they'll say yes 14% of the time, but if you ask them whether they read for pleasure in general, they'll say yes 100%, after all they do it every week!

It would be nice if reading researchers could agree on a standard set of survey questions for the purpose of easy comparison.