Adult smoking rates declined more than 15 percent from 1997 to 2004 but have been stubbornly unchanged since, The Washington Post (NYSE:WPO) reported Friday. The prevalence of cigarette smoking remained relatively unchanged during the early 1990s. but gradually decreased from from 24.7 in 1997 to 20.9 percent in 2004, the newspaper said.

A report by the U.S. Centers for Disease Control and Prevention said about 20.8 percent of U.S. adults are smokers, with 80 percent of them smoking every day. The CDC (NASDAQ:CHINA) said cigarette smoking remains the leading preventable cause of disease and death in the United States, resulting in approximately 438,000 deaths annually.

The CDC attributes the lack of decrease in cigarette use to less funding for comprehensive state programs for tobacco control and an increase in tobacco-industry marketing expenditures. The tobacco industry nearly doubled the amount of money it spends on advertising, from $6.7 billion in 1998 to $13.1 billion in 2005 .