"Smoking Prevalence and Cigarette Consumption in 187 Countries, 1980-2012"  
http://jama.jamanetwork.com/article.aspx?articleid=1812960 
"Conclusions and Relevance  Since 1980, large reductions in the estimated prevalence of daily smoking were observed at the global level for both men and women, but because of population growth, the number of smokers increased significantly. As tobacco remains a threat to the health of the world’s population, intensified efforts to control its use are needed."