Table 2 The representativeness of the sample

Ethnicity distribution

 Minority (%)

8.63

8.40

0.56^a

0.45

Education level

 Middle school and lower (%)

55.58

50.12

0.24^a

0.62

Personal annual income

 Urban area(yuan)

15256.8

13786

0.43^b

0.67

 Rural area(yuan)

5227.8

4140

33.41^b

0.00