Actually since 2014 e-book
Sales have been on a steady decline while print books have enjoyed a comeback. Students even prefer print textbooks even though they are more expensive.
I also noticed an interesting phenomenon as computers, screens, and ebooks began to become popular: the market for paper diaries and journals came into their own. I’ve been keeping journals since the 80s (yes, I’m as old as dirt). It was always a hit and miss thing. Some book stores carried them, most did not. If they did, there were very few to choose from with little variety. Then when screens and ereaders began to grow in popularity, so did the market for journals. Interesting, yes?