I would believe at least 25% any time before 2000. It wasn't really until the late 90s that anti-smoking really got ingrained in the general psyche, and there w

I would believe at least 25% any time before 2000. It wasn't really until the late 90s that anti-smoking really got ingrained in the general psyche, and there was still quite a bit of inertia. Plus kids who were raised by smokers were more likely to smoke.