[maxxxxx]

Seems it goes up during bad times and then down during good times. Makes kind of sense. Pop music often tries to be counterculture.

[randomdata]

That is the basis of the 13-year cycle theory[1], but this is showing that each cycle never recovers, so to speak, resulting in a continual trend towards sadder and angrier.

[1] https://globalnews.ca/news/4082568/the-theory-of-the-13-year...