But total book sales including physical books rose 6% to £3.5bn, according to the data, led by non-fiction gains.
Readers flocked to fitness and self-help books, sending non-fiction sales up 9%, while fiction revenue fell 7%.
Exports rose 6% to £2.6bn, benefiting from a decline in the value of sterling, but also rising in line with domestic growth.
The gain reversed three previous years of export decline.
In 2015, adult colouring books and the 150th anniversary of Alice in Wonderland helped the swell in physical book sales, while ebook sales fell 1.6%.
This time, books on the Danish concept of hygge, which is usually translated into English as “cosiness”, assisted factual sales, as well as fitness books by personal trainer Joe Wicks.
While ebook sales took a hit, digital distribution helped other media.
Journals made a 10% gain last year to £1.2bn, led by a jump in electronic subscriptions, making the market for books and journals worth £4.8bn.
“Last year, one of the most eye-catching figures from our statistics was that physical book sales were increasing while digital book sales dropped,” said chief executive Stephen Lotinga.
“While many will debate as to whether this trend will continue, we should not ignore the fact that digital sales beyond the domestic ebook market are growing.”