Washington ? Americans smoked fewer cigarettes last year than at any time since 1951, and the nation’s per capita consumption of tobacco fell to levels not seen since the early 1930s, the association of state attorneys general reported Wednesday.

Using data the federal government gathers when it collects taxes on cigarette sales, the group found a 4.2 percent decline in 2005 alone and an overall drop of more than 20 percent since tobacco companies reached a legal settlement with the states in 1998.

Association leaders and other tobacco-control advocates hailed the decline as a sign that sometimes-controversial developments triggered by the $246 billion settlement have been effective. The drop was a result, they said, of factors that include the sharply higher cost of cigarettes, restrictions on cigarette advertising and a shift in public perceptions as the dangers of smoking are more aggressively and widely publicized.

“I think we’re reaching a tipping point, where the image of tobacco is that it’s unhealthy and dangerous, and not glamorous like years ago or neutral like the cigarette companies say now,” said Tom Miller, Iowa’s attorney general and co-chairman of the National Association of Attorneys General’s tobacco committee.

Cheryl Healton, president of the American Legacy Foundation, a tobacco-control group initially funded by the legal settlement, said the continuing decline suggests that the national health goal of reducing smoking rates even further by 2010 is within reach.

“We’re on target to exceed the national goal” of having no more than 15 percent of youths and 12 percent of adults smoking, Healton said. Few of the other national health goals adopted in 2000 appear to be achievable, she said, “but this is one battle we’re winning.”

Federal studies show that about 21.7 percent of high school students still smoke, as do 20.9 percent of adults – about 45 million Americans 18 and older.

Tobacco use remains the leading preventable cause of death, causing more than 400,000 deaths a year.