There was plenty of talk of 2014 being a weak year for rap musically, and no matter where you fall on that premise, one thing is for sure: It was a weak year for rap commercially.

For the year, total sales for hip-hop albums were down 24.1 percent, while CDs were down 29.6 percent and digital was down 21.8 percent, according to Billboard, using data from Neilsen Music. While sales obviously aren't what they used to be across the board, that number is particularly staggering since total album sales, across all genres, dropped just 11.2 percent.

So, what's to account for hip-hop lagging behind?

The use of streaming services explains some of the shift. "R&B and hip-hop are popular on streaming sites, and streamed tracks increased 54 percent last year," Billboard reports. And with Beats Music -- a company started by a hip-hop legend -- joining established apps like Spotify in the market this year, some rap fans who hadn't been streaming before (like me) likely got on board (like me).

Plus, it's about the actual albums that came out.

Think back to 2013. Almost all of rap's titans dropped: Jay Z, Eminem, Kanye West, Drake, Lil Wayne. And that's not to mention J. Cole, Rick Ross, Wale, Kid Cudi, Mac Miller, Big Sean, A$AP Rocky and 2 Chainz. Of that group, only Cole, Ross, and Cudi dropped in 2014 (plus Em's label compilation, Shady XV). Of course, there were albums from Nicki Minaj, Jeezy, Wiz Khalifa and Schoolboy Q in 2014 -- but the star power on the whole just wasn't the same.

Hip-hop shouldn't get too down on itself, though. The only major genre to experience an increase in 2014 was pop -- and that was by 0.1 percent, and "entirely due" to Taylor Swift's 1989 being counted as pop instead of country.