The ten year project by researchers from Uppsala University Hospital surveyed 9000 people in 29 cities in Europe, Australia and the United States. It found that the number of smokers dropped during the period from 34 to 28 percent.
More dramatic is the decrease in passive smokers. During the past ten years non-smokers exposed to second hand smoke on a daily basis dropped from 41 to 24 percent.
There are major geographical differences, with more smokers and passive smokers in Spain, France, and Italy, than in Sweden, Australia, or the United States.