In what used to be a pretty popular thing to do in the United States, recent numbers show fewer people are smoking these days.

FOX's Jack Callaghan reports:

Whether its smoking bans, higher cigarette taxes, health warnings or a combination of all of those, the percentage of adults in the United States who smoke has posted its biggest drop in 20 years. 

The number of smokers has been declining steadily for decades, but now only 15 in every 100 people light up. 50 years ago it was nearly triple that rate.

Even with fewer people smoking, the Centers for Disease Control and Prevention says it's still the leading cause of preventable illness and kills nearly half a million people in this country every year.

Jack Callaghan, FOX News.