Table 2. Constitution changes (as weighted %) in each follow-up surveys.

	1992 ( n=3257 )	1994 ( n=2703 )	1997( n=2002 )	2000 ( n=1578 )
Mean Age, y	70.13	70.99	72.5	74.2
Age range, y	55 – 97	57 – 98	60 – 97	63 – 100
Female,% **	51.1	51.6	51.9	52.1
Region,% **
Urban	65.6	66.4	65.6	68.0
Suburban	21.1	20.9	20.7	13.1
Hilly	13.3	12.7	13.7	18.9
Marital Status,%
Married	65.5	65.2	65.8	64.4
Unmarried	34.5	34.8	34.2	35.6
Education,% **
Illiterate	51.1	49.0	46.4	43.5
Primary	27.1	28.0	29.5	30.9
Second and above	21.7	23.0	24.1	25.6

** Compared among each stratified group. P< .01