Unit sales of print books fell 1.9% in the first half of 2019, compared to the same period in 2018, at outlets that report to NPD BookScan. Units dropped to 310.7 million, down from 316.7 million a year ago.

Only one of the major categories—juvenile nonfiction—had a unit sales increase over the first six months of 2018. While sales in adult nonfiction were nearly flat (down only 0.05%), sales in adult fiction fell 5.1%. (Adult unit sales in the first half of 2018 were down 4% from the comparable period in 2017.) Juvenile fiction sales fell 3.6% in the period.

The decline in adult fiction occurred despite a blockbuster new novel. Where the Crawdads Sing by Delia Owens was the top-selling print book in the first half of 2019, selling over 907,000 copies. As has been the case for the last few years, sales of top-selling fiction titles have been fairly high, but sales below the top tier have declined. In the first half of 2019, double-digit unit declines came in five segments, with the biggest drop in science fiction, followed by religion fiction, suspense/thriller, romance, and classics. The largest gains were in action/adventure (up about 41%) and horror/occult/psychological (up about 27%).

The adult nonfiction category held up fairly well considering the comparison it was facing with the first half of 2018, when political books were very hot; Fire and Fury by Michael Wolff and A Higher Loyalty by James Comey sold approximately 1.6 million print copies combined in the first six months of 2018. Offsetting those big numbers in the first half of 2019 were Michelle Obama’s Becoming, which sold more than 888,000 print copies at BookScan outlets, and two books by Rachel Hollis—Girl, Stop Apologizing and Girl, Wash Your Face—which sold nearly 1 million print copies combined in the first half of 2019.

Overall, units fell about 10% in the history/law/political science category, with larger declines in computers and cooking/entertaining. The largest gains were in home/gardening and biography/autobiography/memoir.

The 2.0% gain in juvenile nonfiction was led by 8% increases in both the education/reference/language and holidays/festivals/religion categories. Declines came in the social situations/family/health, biographies/autobiographies, and animals segments.

The 3.6% drop in juvenile fiction was due in part to two unique titles in the first half of 2018. Madeleine L’Engle’s A Wrinkle in Time sold over 514,000 copies, helped by the release of the film based on the book. Likewise, A Day in the Life of Marlon Bundo by Jill Twiss, which benefited from its connection to Last Week Tonight with John Oliver, sold more than 489,000 print copies in the first six months of 2018. For the most part, the top-selling titles in the first half of 2019 were by authors who are mainstays on the juvenile fiction bestseller list—Jeff Kinney, Dav Pilkey, and Sr. Seuss.

At this point last year, it appeared that the decline in mass market paperback might be slowing—unit sales were down only 3% versus the first six months of 2017—but the decline has since accelerated. Mass market units were down 16% in the first half of 2019. Sales of physical audio also continued to tumble, as consumers continue to move to digital audio.