Variable

Persons

Composition (%)

Grade

seventh

93

37.1

eighth

81

32.3

ninth

77

30.7

Sex

boy

131

52.2

girl

120

47.8

Age

≤13 year

12

4.8

14 year~

56

22.3

15 year~

76

30.3

16 year~

81

32.3

17 year~

20

8.0

18 year~

6

2.4

Nationality

Han

57

22.7

Hui

52

20.7

Tibetan

58

23.1

Tu

84

33.5

Origin of student

City

56

22.3

Rural

195

77.7

Only child

Yes

16

6.4

No

235

93.6

Extern student

Yes

141

56.2

No

110

43.8