According to surveys reported in The Atlantic, 23% of the surveyed adults in the US did not read a single book last year.
Without question, the American bookworm is a rarer species than two or three decades ago, when we didn't enjoy today's abundance of highly distracting gadgets. In 1978, Gallup found that 42 percent of adults had read 11 books or more in the past year (13 percent said they'd read more than 50!). Today, Pew finds that just 28 percent hit the 11 mark.
The article tries to downplay the influence of TV and the internet, but I don't see why. I know many, many young adults who don't read books. They read a lot, online, but they don't read books. Alas, in some instances, not even their assigned textbooks.
And given the wealth of material available for information and entertainment (and, yes, education) via other media, I will be surprised if the number who read books doesn't continue to decline.