Also, let's think about what is continually selling at the top rate: the three core books. Establiahed players aren't the ones driving those sales, new players are.
I mean sure folks do buy replacement books (my librarian mother would have a conniption if she saw how some of you abused your books ) but yeah core three purchases are going to be new players.
Is there any evidence of this large group of 45+ year old new players? I’m sure they exist but I’m going to go out on a limb and say they probably aren’t a big group. That 15% for the 45 plus crowd probably looks a lot more like us old farts who’ve been playing for a long time.