Unit sales of print books rose 3% in the third quarter, which ended Oct. 2, 2016, over the comparable period in 2015, at outlets that report to Nielsen BookScan. The increase was lower than the 6% gain posted by print sales in the first half of 2016 over the first six months of 2015 but nevertheless continued the trend of improving sales of print books.

The slower growth rate was reflected in sales by channel. Unit sales rose 4% in the quarter in the retail and club channel, compared to 8% in the first half of the year. Sales through mass merchandisers were off 4% in the quarter, the same level of decline as the first six months of 2016.

The July 31 release of J.K. Rowling’s Harry Potter and the Cursed Child helped lift unit sales by 8% in the juvenile fiction category in the quarter, and it also contributed to the 9% increase in unit hardcover sales. The script book has sold almost four million copies since its release, according to BookScan, which tracks 80%–85% of all print sales.

Sales of adult nonfiction slowed from a growth rate of 12% in the first six months of 2016 to 4% in the third quarter. The segment is home to adult coloring books, and though sales of the category remained solid, their growth cooled from the first six months of the year. Sales in the crafts and hobbies and art and architecture areas, where most of adult coloring book sales are recorded, had increases in the quarter of 32% and 34%, respectively—good gains, but far less than the 133% increase in crafts and hobbies sales in the first half of 2016 and the 51% gain in the art and architecture segment.

Unit sales of adult fiction fell 3% in the quarter, a greater decline than in the first six months of the year. The segment has been dealing with the lack of a new breakout hit throughout 2016, and that continued into the third quarter. The trade paperback edition of The Girl on the Train, released in early July, was the top-selling adult novel in the quarter, selling more 600,000 copies. Last summer, Go Set a Watchman and Grey each sold more than one million copies, while the hardcover edition of The Girl on the Train sold more than 275,000 copies.

Sales in the juvenile nonfiction category slowed noticeably in the third quarter, falling from a 9% increase in the first half of the year to a 1% decline. Part of the reason for the drop is that a number of adult coloring books had previously been included in the segment, but all newer adult coloring books are now in the adult nonfiction segment.

Despite the slower growth of print sales in the third quarter compared to the first half of 2016, total unit sales through the first nine months of 2016 were up 5% over the comparable period in 2015. The adult nonfiction category led the way with a 9% increase, while unit sales rose 6% in juvenile nonfiction and 4% in juvenile fiction. Unit sales fell 1% in adult fiction.

Third-Quarter Print Unit Sales by Channel

2015 2016 Change
Total 153,460 157,824 3%
Mass Merch./Other 23,037 22,179 -4%
Retail & Club 130,422 135,645 4%

Third-Quarter Print Unit Sales by Category

2015 2016 Change
Adult Nonfiction 61,517 64,136 4%
Adult Fiction 37,087 35,897 -3%
Juvenile Nonfiction 11,800 11,931 -1%
Juvenile Fiction 37,585 40,754 8%

Third-Quarter Print Unit Sales by Format

2015 2016 Change
Hardcover 36,822 40,018 9%
Trade Paperback 89,296 91,375 2%
Mass Market Paperback 16,472 15,319 -8%
Board Books 6,525 6,650 2%
Audio 1,053 930 -12%