Table 1. Demographic data in the two rounds of surveys.

			Percentage (%)
			City	Town	Country
Round I			(n = 1487)	(n = 916)	(n = 1313)
(n = 3716)	Gender	Male	48.8	46.8	46.8
		Female	51.2	53.2	53.2
	Age	Under 19	2.4	5.1	5.3
		20–29	21.8	24.9	18.7
		30–39	25.7	25.3	23.9
		40–49	27.8	22.8	25.3
		50–59	20.8	19.5	23.5
		Over 60	1.3	1.9	2.2
		Unknown	0.3	0.4	1.1
	Education	Below senior high school	25.7	54.3	75.6
		Senior high school and above	74.2	45.0	22.5
		Unknown	0.1	0.8	1.9
Round II			(n = 639)	(n = 399)	(n = 414)
(n = 1452)	Gender	Male	44.9	47.1	49.5
		Female	55.1	52.9	50.5
	Age	Under 19	3.1	10.0	1.7
		20–29	21.4	34.8	15.5
		30–39	28.3	26.8	28.3
		40–49	24.6	16.0	26.1
		50–59	20.7	11.3	26.3
		Over 60	1.9	1.0	2.2
	Education	Below senior high school	32.1	34.1	88.6
		Senior high school and above	67.9	65.9	11.4