Table 2.

Basic social and demographic characteristics of the study population by sex

Variables	Male		Female		Total
	n	%	n	%	n	%
	7118	39	10,848	62	17,966	100
Age
≤ 19	1879	26	3621	33	5500	31
20 ~ 21	4074	57	6023	56	10,097	56
≥ 22	1165	16	1204	11	2369	13
Monthly expenditure
< 1000	3149	44	5729	53	8878	49
1000 ~ 2000	3367	47	4375	40	7742	43
> 2000	602	8	744	7	1346	7
Alcohol
non-drinker	922	13	4435	41	5357	30
occasional drinker	3620	51	5642	52	9262	52
infrequent drinker	2235	31	700	6	2935	16
frequent drinker	341	5	71	1	412	2
Tobacco
never	5724	80	10,655	98	16,379	91
1 ~ 10cigarretes/day	1106	16	161	1	1267	70
> 10cigarretes/day	288	4	32	0	320	2
Hometown
urban	2923	41	4203	39	7126	40
suburban	2122	30	3472	32	5594	31
rural	2073	29	3173	29	5246	29
Family Type
nuclear/extended family	6351	89	9729	90	16,080	90
other	767	11	1119	10	1886	10
Parents’ Education
primary school and be	740	10	1115	10	1855	10
middle school	2174	31	3693	34	5867	33
high school	2243	32	3474	32	5717	32
vocational school and	1961	28	2566	24	4527	25
Sexual Orientation
heterosexual	6428	90	9660	89	16,088	90
homosexual	291	4	158	1	449	2
bisexual	277	4	634	6	911	5
not sure	122	2	396	4	518	3