Table 1.

Characteristic of the Research Group in Reference to Smoking Status.

Smoking status	N (%)	Age (years) M (SD), min.–max.	Years of smoking M (SD), min.–max.
Never-smokers	83 (27.3%)	44.0 (8.7), 25–60	n.a.
Active-smokers	95 (31.3%)	46.5 (8.8), 24–61	22.6 (10.1), 1–45
Ex-smokers	126 (41.4%)	46.9 (7.6), 26–59	14.5 (8.6), 1–36

Note. n.a. = not applicable.