From 2005 to 2010, the percent of U.S. adults identifying themselves as smokers fell from 20.9% to 19.3% -- about 3 million fewer smokers than would be expected. The results come from the CDC's national telephone health surveys. More remarkably, adults reported smoking far fewer cigarettes: The proportion of adults reporting smoking more than a pack-and-a-half (30 cigarettes) fell from 12.7% in 2005 to 8.3% in 2010.