Stats clearly show that the lower you are on the country's socio-economic ladder the more likely you are to smoke (tobacco).
To give a practical example...I worked for decades at a major (well known) hospital.When I started about half of the physicians,and two-thirds of the nurses,with whom I worked smoked.When I left a few years back *none* of the physicians,and no more than a quarter of the nurses,smoked.
Of course the health care factor probably played a role but it's also true that physicians are at the top of that ladder and nurses make pretty good money as well.
At hospitals now one pays a four thousand dollar additional premium on health insurance if on smokes.
Of course there is no premium on marathoners, who need new joints every ten to twenty years, or child soccer players who blow out their knees by fifteen.