In 2015, 3.5% of U.S. adults were current e-cigarette users.
Among adult e-cigarette users overall, 58.8% also were current cigarette smokers, 29.8% were former cigarette smokers, and 11.4% had never been cigarette smokers.
Among current e-cigarette users aged 45 years or older, 98.7% were either current or former cigarette smokers, and 1.3% had never been cigarette smokers. In contrast, among current e-cigarette users aged 18–24 years, 40% had never been cigarette smokers.
NCHStats 