Where would one find recent statistical data on how many people are

habitual cigarette smokers?

although a current almanac might have it or also a SAUS (statistical abstract of the US) both of those I have at home but are probably 5 years old. Try some of the Surgeon Generals Reports linked, of all places, at Phillip Morris.com http://www.philipmorrisusa.com/en/health_issues/surgeon_general_reports.asp

even though my head is exploding just thinking about it.

I guess the prevalence of teenagers and adults who smoked in 1997 was around 25%

I expected better from the internets.
My SAUS says 25.9% in 1999. It has it by state and the leading state is Kentucky with 33.1 followed by its neighbor Ohio 30.6 and Missouri at 30.6. For people 12 and over the number is 29.7% and in 1998 69.7% of people 12 and over had tried smoking and another 17.2 (or perhaps many of the same) had tried chewing tobacco with 2.2% current users. The trend is way down with 78% having tried cigs in 1985 and 38.7% users (both being groups of people over age 12).

Alcohol use has been more consistent with 81.3% having tried it and 52% being current users. Well even both of those are down from 1985 from 84.9% and 60.2%. Marijuana use is down from 12.1% to 7%, althoug about the same percentage (35%) report having tried it.

but it is as I suspected...less than a third still smoke.