PW's weekly look at print book sales based in data from Nielsen BookScan.

Unit Sales of Print Books by Category

Category Aug. 21, 2011 Aug. 19, 2012 % Chge Week % Chge YTD
Adult Nonfiction 6,309 4,510 -29% -16%
Adult Fiction 3,915 2,925 -25 -14
Juvenile Fiction 2,824 2,371 -16 -3
Juvenile Nonfiction 687 650 -5 3

Unit Sales of Print Books by Format

Format Aug. 21, 2011 Aug. 19, 2012 % Chge Week % Chge YTD
Hardcover 3,084 2,409 -22% -7%
Trade Paperback 8,679 6,590 -24 -13
Mass Market Paperback 1,846 1,296 -30 -25
Board Books 284 269 -5 0
Audio 109 88 -19 -9

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.