Do you have any data to back up your first sentence, or is this your personal opinion? People have been claiming this for decades, but I'm not familiar with the

Do you have any data to back up your first sentence, or is this your personal opinion? People have been claiming this for decades, but I'm not familiar with the sources on this. It looks like other people here would be interested too. Also, are you defining "reading culture" as leisure reading? Or something else?