In 2004, only about 45% of people in the United States between the ages of 12 and 17 owned cell phones. At that time, most had to rely on landline telephones. Just 4 years later, that percentage climbed to about 71%. That same year, 2008, about 77% of adults owned a mobile phone. In the year 2013, 91% of adults in the United States owned a mobile phone. Almost 60% of those with a mobile had a smartphone. A National Health Interview Survey of 19,956 households by the Centers for Disease Control and Prevention released May 4, 2017 showed only 45.9 percent of U.S. households still had landlines, while 50.8 percent had only cell phones. Over 39 percent had both.