Table 7.

Details about the vulnerable index of the four cities

	Beijing	Wuhan	Dalian	Urumqi
Vulnerable index	0.1566	0.8733	0.1119	0.1951
DAY	25	182	15	31
NUMBER	335	81,260	93	826
Regression analysis	Multiple R	R Square	Adjusted R square	Standard error
	0.999952	0.999904	0.999713	0.006115
	df	SS	MS	F
	2	0.390899	0.19545	5226.629