E-Reading: How has it changed in recent years?

When Out of Print was released, 20% of American adults own an e-reader and 20% own a tablet. Since then, the use of tablets and cellphones to read books has increased substantially:

• In 2011, 4% read on a tablet, 7% on an e-reader, 7% on a desktop or laptop, and 5% on a cellphone.
• In 2016, 15% read on a tablet, 8% on an e-reader, 11% on a desktop or laptop, and 13% on a cellphone.