Table 1 Socio-demographic information of participants (n = 529)

Gender

 Male

321

61.68

 Female

208

39.32

Nationalities by continent

 Asian

323

61.06

 European

27

5.10

 North America

12

2.27

 South America

7

1.32

 Africa

153

28.92

 Oceania

7

1.32

Learning type

 Preparatory student

170

32.14

 Exchange student

33

6.24

 Undergraduate student

164

31.00

 Bachelor’s degree

87

16.45

 Doctoral

45

8.51

 Other

30

5.67

Length of residence in China

 1 year/below

359

67.86

 2 years

40

7.56

 3 years

28

5.29

 4 years

47

8.88

 5 years

28

5.29

 6 years/over

27

5.10

Proficiency in Chinese

 Very bad

24

4.54

 Poor

34

6.43

 Relatively bad

65

12.29

 Normal

174

32.89

 Better

97

18.34

 Good

103

19.47

 Very good

32

6.05