Table 1 Basic characteristics of urban and suburban subpopulations in the NSPGDC at each survey year, 1985–2015

Sample sizes

79,194

79,154

69,760

83,628

73,680

78,208

69,015

78,146

 Exclusive or predominant breastfeeding

33.6

53.5

32.8

52.9

60.2

63.1

42.5

53.8

 Partial breastfeeding

43.4

32.7

47.1

34.2

33.1

25.6

41.9

31.0

 Formula feeding

23.0

13.8

20.1

12.9

6.7

11.3

15.6

15.2

 Father

–

29.4

49.3

69.6

–

2.9

10.8

37.2

 Mother

–

21.9

43.7

67.9

–

1.4

8.1

35.8

 Annual family income ≥50 thousand Yuan (%) ^a

–

–

35.8

78.2

–

–

9.6

61.5