PW's weekly look at the sales of print books based in numbers from Nielsen BookScan.

Unit Sales of Print Books by Category

Category July 17, 2011 July 15, 2012 % Chge Week % Chge YTD
Adult Nonfiction 4,205 3,802 -10% -14%
Adult Fiction 3,264 3,396 4 -12
Juvenile Fiction 2,447 2,378 -3 2
Juvenile Nonfiction 595 697 17 5

Unit Sales of Print Books by Format

Category July 17, 2011 July 15, 2012 % Chge Week % Chge YTD
Hardcover 2,598 2,284 -12% -3%
Trade Paperback 6,316 6,492 3 -9
Mass Market Paperback 1,594 1,366 -14 -23
Board Books 243 269 11 3
Audio 92 88 -4 -7

Category segment excludes “other,” which includes audio, maps, calendars, and other miscellaneous categories. Format excludes calendars, boxed sets, and other formats (i.e., maps, minibooks).
Source: Nielsen BookScan and Publishers Weekly. Nielsen BookScan’s U.S. Consumer Market Panel covers approximately 75% of the print book market and continues to grow.