Male

Female

School year (and age, y)

Rural

Metropolitan

All

Rural

Metropolitan

All

1 (6)

85.30 ± 15.69

(17, 151)

87.33 ± 15.81

(62, 1297)

86.90 ± 15.71

(79, 1448)

71.61 ± 19.79

(16, 139)

78.00 ± 14.41

(68, 1392)

76.78 ± 15.64

(84, 1531)

2 (7)

86.38 ± 14.34

(18, 187)

87.67 ± 16.01

(68, 1363)

87.40 ± 15.61

(86, 1550)

76.50 ± 15.19

(18, 174)

84.23 ± 15.70

(74, 1499)

82.71 ± 15.82

(92, 1673)

3 (8)

88.97 ± 13.87

(18, 173)

90.30 ± 14.08

(80, 1710)

90.06 ± 13.98

(98, 1883)

84.52 ± 17.43

(18, 162)

86.47 ± 14.38

(85, 1777)

86.13 ± 14.88

(103, 1939)

4 (9)

91.83 ± 14.88

(19, 199)

89.94 ± 13.51

(75, 1524)

90.32 ± 13.74

(94, 1723)

83.95 ± 14.01

(18, 139)

89.86 ± 13.46

(82, 1644)

88.80 ± 13.68

(100, 1783)

5 (10)

93.70 ± 16.22

(17, 154)

91.69 ± 14.68

(77, 1544)

92.05 ± 14.90

(94, 1698)

89.33 ± 12.00

(17, 138)

88.94 ± 14.33

(85, 1793)

89.01 ± 13.92

(102, 1931)

6 (11)

92.98 ± 15.80

(16, 131)

91.74 ± 13.31

(72, 1465)

91.96 ± 13.70

(88, 1596)

91.04 ± 12.70

(16, 130)

91.54 ± 11.98

(79, 1773)

91.45 ± 12.04

(95, 1903)

7 (12)

93.34 ± 17.54

(16, 118)

91.44 ± 12.47

(68, 1367)

91.80 ± 13.48

(84, 1485)

95.72 ± 15.72

(15, 114)

92.46 ± 12.72

(75, 1753)

93.00 ± 13.22

(90, 1867)

1 - 7 (6 - 12)

90.29 ± 15.41

(121, 1113)

90.10 ± 14.29

(502, 10,270)

90.14 ± 14.51

(623, 11,383)

84.46 ± 16.86

(118, 996)

87.56 ± 14.51

(548, 11,631)

87.01 ± 14.99

(666, 12,627)