years to quit smoking
15.7
13.2
22.6
13
10.7
18.1
14.7
7
17.3
7.5
21.8
12.3
19.8
13.8
16
15.5
13.1
20.7
15.5
9.8
11.9
16.9
7
19.3
13.2
14.6
20.9
15.4
13.3
11.6
10.9
21.6