>I can not imagine that someone who smokes a few cigarettes in their 20s loses the same per cigarette as someone who smokes for years. Realistically even in a

>I can not imagine that someone who smokes a few cigarettes in their 20s loses the same per cigarette as someone who smokes for years. Realistically even in a large enough sample set you won't see a "jump" or "cliff". It'll just look like blurry data. At some point, you'll be like obviously this is making a difference, but it'll be this very wide band and putting drawing a line will never be right. You'll end up saying something like >500-12,000 smoked means X minutes per cig. The band will be so sloppy it's better to just go linear and say an overly simplistic answer.