You can put it any way you like, but we know that the US book market is about the same size as what it was 20 years ago [1]. So reading decliced as much as book prices increased. Unless you're talking about another country, of course.

[1]: https://ideas.bkconnection.com/10-awful-truths-about-publish... It assumes book price trend = CPI, but I don't buy it. Recreational books are one of the few things that have become cheaper [2], likely due to e-books.

[2]: https://www.in2013dollars.com/Recreational-books/price-infla...