Variable

Age, years

≤20 (n = 76)

21 - 30 (n = 64)

31 - 40 (n = 217)

41 - 50 (n = 176)

≥50 (n = 9)

No.

%

No.

%

No.

%

No.

%

No.

%

Education

Illiterate

2

2.6

0

0.0

7

3.2

11

6.3

8

88.9

Primary school

13

17.1

12

18.8

109

50.2

113

64.2

1

11.1

Secondary school

55

72.4

43

67.2

85

39.2

41

23.3

0

0.0

Junior college and higher

6

7.9

9

14.0

16

7.4

11

6.3

0

0.0

Job

Self-employed

0

0.0

1

1.6

69

31.8

85

48.3

9

100.0

Builder

18

23.7

23

35.9

78

35.9

14

8.0

0

0.0

Catering waiter

54

71.1

32

50.0

21

9.7

17

9.7

0

0.0

Official

0

0.0

1

1.6

13

6.0

21

11.9

0

0.0

Part-time job

4

5.2

7

10.9

36

16.6

39

22.1

0

0.0

Monthly income (CNY)

≤500

5

6.6

1

1.6

9

4.1

0

0.0

0

0.0

500 - 2000

71

93.4

60

93.7

187

86.2

167

94.9

9

100.0

2000 - 5000

0

0.0

3

4.7

21

9.7

9

5.1

0

0.0

≥5000

0

0.0

0

0.0

0

0.0

0

0.0

0

0.0