How many years earlier, on average, do smokers die than nonsmokers?

10 years

Explanation:

"People who smoke take at least 10 years off their life expectancy, a new study has found. On the other hand, those who kick the habit before age 40 reduce the excess risk of death associated with continued smoking by about 90%, according to the study in Thursday's New England Journal of Medicine."

Hope this makes your day better and helps.

all the above is what i would say