Trade book sales rose 6.9%, to $15.05 billion, in 2012, according to figures released by BookStats, the Association of American Publishers/Book Industry Study Group statistics program. Unit growth in the year was put at 8.1%. Total industry sales fell just under 1% in 2012, to $27.12 billion, due mainly to a sales decline in the K-12 market which has been hurt by weak state and local budgets.

The first release of data by BookStats--more figures will be coming in the next few weeks--provided more details on how the growth of e-books has affected the trade market. Total e-book sales rose 44.2% in 2012, to $3.04 billion and accounted for 20% of trade revenue in the year, up from 16% in 2011. The gain in e-book sales offset a flat performance by print sales which held virtually even at $12 billion between 2011 and 2012.

The BookStats figures also show the importance adult fiction has played in the growth of e-books, with sales in that segment up to $1.8 billion in 2012, an increase of 41.8% over 2011. Sales in the children’s/young adult segment had the fastest gain in the year, with sales up 117%, to $469.1 million. Sales of adult nonfiction rose 22.3%, to $592.2 million.

BookStats did not have all bad news for print formats. Sales of hardcovers rose 1.3% in the year, to $5.06 billion, and trade paperback sales increased slightly, up 0.4%, to $4.96 billion. Figures for mass market paperback are still being finalized, but will certainly show a sales decline. Sales of downloadable audio rose 21.8% in 2012, to $240.7 million, but there was no data on the performance of physical audio.

The BookStats figures also confirmed what data released by Bowker Market Research last week showed about the growing importance of online retailers to book sales. According to BookStats, sales through online retailers rose 21.3% in 2012, to $6.93 billion, while sales through bricks-and mortar outlets fell 7.0%, to $7.47 billion. The collapse of Borders in 2011 and greater use online retailers by readers to buy both e-books and print books are two of the major factors behind the swing in where books were bought last year.

AAP/BISG will release the full BookStats report in June, while the interactive data dashboard will be live some time the week of May 20.