Table 1.

The Mean and median of disability index and rank correlation between disability index of 1996

	year	1996	1997	1998	1999	2000	2001	2002
Male (n = 453)	Mean	0.006	0.006	0.010	0.012	0.015	0.018	0.027
	SD	0.035	0.034	0.053	0.058	0.060	0.067	0.080
	Median	0.003	0.003	0.003	0.004	0.007	0.008	0.012
	Correlation*		0.629	0.475	0.433	0.363	0.324	0.327
	P		<0.001	<0.001	<0.001	<0.001	<0.001	<0.001
Female (n = 747)	Mean	0.007	0.009	0.009	0.011	0.016	0.022	0.036
	SD	0.031	0.032	0.035	0.043	0.055	0.061	0.082
	Median	0.005	0.006	0.006	0.007	0.010	0.014	0.020
	Correlation*		0.615	0.521	0.460	0.363	0.324	0.256
	P		<0.001	<0.001	<0.001	<0.001	<0.001	<0.001

*Spearman's rank correlation between disability index of 1996