IOv
	Survey1	Survey2	Survey3
R	0.822	0.835	0.825
R2	0.676	0.697	0.681
adjusted R2	0.676	0.697	0.681
β (standardized partial regression coefficient)
IPs	0.682 **	0.689 **	0.632 **
	[1]	[1]	[1]
IPh	0.167 **	0.174 **	0.225 **
	[2]	[2]	[2]
Notes: **: p < 0.01.