The AAP released their estimates for the US book market for 2011, and it’s mixed news all around. eBook and audiobooks saw a nice bump in sales last year, but several of the print segments continue to decline.

eBooks grew slightly over November 2011, closing out the year with an increase of 117% over 2010. Audiobooks also continue to grow, and they’re showing a solid 25% increase year over year.

On the other hand, print continues its decline in hardcover, paperback, and massmarket. This decline has been seen in most months of 2011, and it worries some industry analysts.