The simultaneous advent of streaming music and the vinyl renaissance has led to some very interesting recording industry statistics over the past few months. Last month, the RIAA reported that vinyl revenues outpaced sales from streaming services, despite actual streams vastly outnumbering physical vinyl sold. Now, Nielsen has released data revealing that, for the first time ever, old music (the “catalog,” defined as music more than 18 months old) outsold new releases in 2015.

It’s important to note that Nielsen’s numbers here don’t include streaming numbers, but that in itself is telling of current trends: an easy-to-draw hypothesis from these stats is that new music exists primarily in the streaming realm, rather than in album downloads or physical copies. And as 2016 has progressed and seen such things as Kanye’s The Life of Pablo shenanigans, exclusive streaming rights, like Rihanna and Beyoncé with Tidal and Drake with Apple Music, and the fact that the Beatles dominated Spotify in their first 100 days on the service, streaming music’s hold on the future seems to be growing tighter.

So who’s buying up all the digital downloads and physical copies of old music? For one, it could be older consumers, the same people who were likely responsible for CDs (still) generating $1.52 billion in sales last year, preferring familiar songs to new ones and still adhering to the traditional methods of music consumption. But another reason might be the vinyl boom, a trend that has done wonders for back catalogs—for instance, Pink Floyd’s Dark Side of the Moon was the third-best-selling vinyl record of 2015. With a limited number of vinyl presses in the country strapped with the burden of pumping out all the new releases, it makes sense that many of the LPs and EPs purchased would be older.

Another theory, for which we have no factual basis: what if there’s simply enough old music now to balance out anything new that comes out? Perhaps we reached a point where there simply weren’t enough days in 2015 for new music releases that could outsell hundreds of years of musical history. If so, this trend of old music trumping new could just be getting started. And to be honest, we wouldn’t be surprised if it holds for 2016, just based on the deaths of David Bowie and Prince—the latter of whom is posthumously dominating the Billboard 200 right now.