Table 1.
Sample characteristics
| n | % of boys | |
|---|---|---|
| Grade 2 | 835 | 54.1 |
| Grade 3 | 836 | 51.1 |
| Grade 4 | 853 | 48.9 |
| Grade 5 | 848 | 49.9 |
| Grade 6 | 913 | 49.7 |
| Total | 4,285 | 50.7 |
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