There’s no doubt that American attitudes on smoking tobacco have shifted in the past 38 years. What was once seen as the cool, mature thing to do is now seen as a dirty habit committed by a person with poor judgment. These attitudes are just some of the findings of the latest University of Michigan, Ann Arbor, survey that looks at how teen smoking — among other substance use — has dropped considerably between 1975 and 2013.

The University of Michigan’s Monitoring the Future study is based on annual surveys of between 40,000 and 50,000 eighth, 10th, and 12th grade students throughout 400 schools. It asked them if they had smoked a cigarette within the 30 days — labeled “current smoking” — prior to being surveyed. For all three grades combined, smoking rates dropped over the past year from 10.6 percent to 9.6 percent.

“This year’s decline means that the number of youngsters actively smoking has dropped by almost one-tenth over just the past year, and it follows a decline of about the same magnitude last year,” Lloyd Johnston, lead investigator of the study, said in a statement. “Since the peak year in 1997, the proportion of students currently smoking has dropped by two-thirds — an extremely important development for the health and longevity of this generation of Americans.”

Cigarette causes nearly 440,000 deaths in the U.S. each year, which is more than those caused by illegal drug use, alcohol use, motor vehicle injuries, firearm-related injuries, and human immunodeficiency virus (HIV) combined. Furthermore, it damages nearly all parts of the body, and increases risk for coronary heart disease, stroke, lung cancer, and other types of cancer and respiratory disease, according to the Centers for Disease Control and Prevention.

According to the research, which was funded in part by the National Institute on Drug Abuse, rates of current smoking fell nearly 80 percent in eighth graders, 70 percent in 10th graders, and more than 50 percent in 12th graders since their peaks between 1996 and 1997.

Although the researchers say that the 2009 increase in federal tax on tobacco products could play a part, declining rates may also be due to shifting attitudes about smoking cigarettes. Almost two-thirds of eighth graders, and 75 percent of 10th and 12th graders said that they saw a great risk of harm to the user from smoking a pack each day. More Than 80 percent of students in each grade also said that they personally disapprove of smoking. Other negative attitudes toward smoking included preferences to date a nonsmoker, and a dislike for being around people while they smoke.

On the other hand, marijuana use increased over the past year in eighth and 10th graders, going from 11.4 percent to 12.7 percent and 28 percent to 29.8 percent, respectively, The Week reported. Meanwhile, the study found that more than 60 percent of high school seniors felt that smoking marijuana daily wasn’t harmful to a person’s health — three times more seniors smoked weed daily this year when compared to 20 years ago. These rising figures did not hold true for other drugs, such as synthetic marijuana and bath salts, which saw a significant decline; or inhalants, salvia, narcotics, and hallucinogens, which remained steady.

Lastly, the study found that fewer teens were drinking alcohol or binge drinking, putting teen drinking rates at their lowest since the mid-1990s, according to a statement. Although there wasn’t a definitive reason for this, the researchers cite that perceived availability of alcohol has been declining in recent years, especially in the lower grades.