I listen to tons of new music - current, young artists, who've released all or nearly all of their music the past 5-10 years, that's most of my listening.
In spite of that, I expect that 70%+ of my listening is over this arbitrary cutoff and would count as "catalog" . Even if I find a new band opening at a show - probably they've been around a couple years and if I dive into them the majority of their music is >18 months.
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The other aspect is I'd like to see age demographic data for the music stats. Older people have largely only gotten into Spotify and the like more recently. Are young people listening to less new music, or is this just a reflection of now having a wider age range in streaming stats?