TABLE 1.

Smoking Initiation and Progression Prevalence of Sample

	% Initiated smoking (indicated having ever smoked)
	Age 12–13	Age 14–15	Age 16–17	Age 22–32
Total sample	10.4	27.4	46.6	79.1
MZ males	12.0	32.0	48.0	77.5
MZ females	8.6	22.2	35.0	76.6
DZ males	11.2	31.3	46.8	84.2
DZ females	8.0	26.8	32.6	78.5
DZ opposite sex	12.4	27.8	50.2	82.6
	% Non-current smokers (0 cigarettes smoked daily)
	Age 12–13	Age 14–15	Age 16–17	Age 22–32
Total sample	91.2	85.1	84.3	58.0
MZ males	80.6	86.4	83.7	59.3
MZ females	96.9	88.1	88.1	62.3
DZ males	100.0	83.9	77.8	53.1
DZ females	100.0	86.0	87.2	58.0
DZ opposite sex	89.7	79.5	84.4	52.3
	% Current, light smokers (1–5 cigarettes smoked daily)
	Age 12–13	Age 14–15	Age 16–17	Age 22–32
Total sample	8.8	8.2	5.9	13.3
MZ males	19.4	6.8	7.8	15.7
MZ females	3.1	5.9	2.4	10.4
DZ males	0.0	9.7	7.4	12.5
DZ females	0.0	8.0	2.1	12.5
DZ opposite sex	10.3	12.3	7.1	16.5
	% Current, heavy smokers (5+ cigarettes smoked daily)
	Age 12–13	Age 14–15	Age 16–17	Age 22–32
Total sample	0.0	6.7	9.8	28.8
MZ males	0.0	6.8	8.5	25.0
MZ females	0.0	5.9	9.5	27.3
DZ males	0.0	6.5	14.8	34.4
DZ females	0.0	6.0	10.6	29.5
DZ opposite sex	0.0	8.2	8.4	31.3