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Developmental trajectories of cigarette smoking extending from adolescence to age 37 years (N = 806). Note. Smoking score categories: 5.00 = 1.5 packs a day or more, 4.00 = one pack per day, 3.00 = 1/2 pack per day, 2.00 = 1–5 cigarettes a day, 1.00 = less than daily smoking, and 0.00 = none.
