Study on the Operation Efficiency of Toll Roads in China from the Perspective of Scale Economy

Table 3

Descriptive statistics of the main variables.

	Num.	Mean	Std. dev.	Min	Max
TFP	174	1.069116	0.457933	0.349773	3.284483
SEC	174	1.025559	0.185348	0.416441	1.592271
Toll	203	0.035724	0.024199	0.003651	0.107734
Urban	203	57.38752	12.46630	33.80282	89.60663
Unemploy	203	3.336453	0.633825	1.200000	4.500000
Eply	203	2.057652	0.644237	0.628608	4.390450
Toll_Sation	203	57.34975	58.48951	12.00000	334.0000
Ltc	203	7.219520	0.970183	4.620945	9.053704
Ave_Salary	203	1.114986	0.117489	0.733414	1.423991