Male

Female

School year (age, y)

Rural

Metropolitan

All

Rural

Metropolitan

All

1 (6)

96.48 ± 10.11

(17, 151)

93.78 ± 12.95

(62, 1337)

94.36 ± 12.39

(80, 1488)

78.64 ± 9.32

(16, 139)

83.87 ± 11.21

(68, 1440)

82.87 ± 11.02

(85, 1579)

2 (7)

87.83 ± 6.11

(18, 187)

90.32 ± 11.72

(68, 1406)

89.80 ± 10.80

(87, 1593)

81.33 ± 6.93

(18, 174)

87.94 ± 11.45

(74, 1552)

86.65 ± 11.00

(93, 1726)

3 (8)

91.18 ± 7.94

(18, 178)

92.72 ± 10.34

(80, 1806)

92.44 ± 9.92

(102, 1984)

86.44 ± 4.70

(19, 165)

89.45 ± 10.69

(85, 1862)

88.93 ± 9.96

(107, 2027)

4 (9)

93.51 ± 8.60

(19, 207)

92.50 ± 9.87

(75, 1622)

92.70 ± 9.59

(98, 1829)

91.37 ± 6.20

(19, 147)

92.14 ± 10.76

(82, 1761)

92.00 ± 10.07

(104, 1908)

5 (10)

91.18 ± 7.67

(17, 154)

91.10 ± 10.92

(77, 1634)

91.12 ± 10.37

(96, 1788)

88.19 ± 5.29

(17, 138)

90.72 ± 11.39

(85, 1862)

90.30 ± 10.64

(104, 2000)

6 (11)

86.55 ± 6.31

(16, 131)

90.28 ± 9.55

(72, 1552)

89.60 ± 9.13

(90, 1683)

88.49 ± 6.15

(16, 130)

90.57 ± 9.62

(79, 1849)

90.22 ± 9.13

(97, 1979)

7 (12)

82.66 ± 11.73

(16, 137)

89.30 ± 10.67

(68, 1394)

88.03 ± 11.12

(86, 1531)

91.55 ± 7.82

(16, 128)

91.19 ± 10.66

(75, 1793)

91.25 ± 10.21

(92, 1921)

1 - 7 (6 - 12)

90.05 ± 9.31

(121, 1145)

91.43 ± 10.88

(502, 10751)

91.16 ± 10.6

(639, 11896)

86.54 ± 7.96

(121, 1021)

89.55 ± 11.05

(548, 12119)

89.02 ± 10.63

(682, 13140)