The proportion of Americans who read e-books is growing as ownership of devices increases, but “print remains the foundation of Americans’ reading habits,” according to a recent Pew Research Center study. In fact, in every age, race/ethnicity, gender, education level, household income and community demographic reported, print books significantly outperform all other book formats.

The survey found that 28% of adults read an e-book in 2013, up from 23% in 2012. Meanwhile, seven in 10 Americans reported reading a book in print, up 4% from 2012, while 14% of adults listened to an audiobook. Only 4% reported their reading habits as “e-book only.”

The survey showed that 50% of Americans now have a dedicated handheld device for reading e-content—defined by the survey as either a tablet or an e-reader—up from 43% in September.

Overall, 76% of adults read a book in some format in 2013, with the “typical American adult” reading or listening to five books, and the average for all adults being 12 books. The average number of books read has not changed significantly throughout the past few years, however.

Conducted at the beginning of January, the survey found that that 42% of adults now own tablet computers, up from 34% in September. Meanwhile, the number of adults with a dedicated e-book reading device—like a Kindle, Nook or Kobo reader—jumped from 24% to 32% during the same period.

The survey also found that “e-book readers who own tablets or e-readers are very likely to read e-books on those devices—but those who own computers or mobile phones sometimes turn to those platforms, too.” Women are more likely than men to have read a book in the 12 months prior to the survey, and those with higher levels of income and education are also more likely to have done so.

The phone survey of more than 1,000 American adults was conducted Jan. 2-5 by Princeton Survey Research Associates International.