Table 1 Demographic, socioeconomic and reproductive characteristics, by rural/urban

Number of participants

47,150

37,381

84,531

 35–36

15.27

13.54

14.50

 37–38

18.67

16.88

17.88

 39–40

20.24

16.91

18.77

 41–42

21.80

22.08

21.92

 43–45

24.02

30.60

26.93

 Mean (SD)

40.01 (0.94)

40.43 (3.03)

40.20 (2.99)

 <20,000

65.22

38.40

53.36

 ≥20,000

34.78

61.60

46.64

 Primary school and below

43.63

14.01

30.53

 Middle school

44.28

36.62

40.89

 High school and above

12.09

49.37

28.58

 Agricultural and related workers

69.76

3.19

40.32

 Factory worker

14.08

39.18

25.18

 Professional worker

5.42

29.98

16.28

 Housewife

6.60

6.31

6.47

 Unemployed

0.41

10.86

5.03

 Other or not stated

3.73

10.49

6.72

 0

90.96

96.25

93.30

 1

7.29

3.02

5.40

 ≥2

1.75

0.73

1.30