Overall, about 19 percent of adults said they smoked last year, down from about 21 percent in 2005. The rate for smoking 30 or more cigarettes daily dropped to about 8 percent from almost 13 percent.
The report from the Centers for Disease Control and Prevention compared last year with 2005 and says the decline means 3 million fewer adults were smoking.
The recent trend has been mostly flat. CDC chief Dr. Thomas Frieden says any decline is a good step. But he also notes that you don't have to be a heavy smoker to get smoking-related diseases.

http://accesswdun.com/article/2011/9/241669