Table 1 Sample composition
Cohort Number | Years in which the surveys were conducted | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
2015 | 2016 | 2017 | 2018 | 2019 | Total | |||||||||||
Grade | n | Grade | n | Grade | n | Grade | n | Grade | n | |||||||
Boys | Girls | Boys | Girls | Boys | Girls | Boys | Girls | Boys | Girls | |||||||
1 | 8 | 447 | 450 | 9 | 446 | 452 | Â | Â | Â | Â | Â | Â | Â | Â | Â | 1795 |
2 | 7 | 492 | 418 | 8 | 492 | 415 | 9 | 492 | 410 | Â | Â | Â | Â | Â | Â | 2719 |
3 | 6 | 414 | 467 | 7 | 394 | 454 | 8 | 399 | 441 | 9 | 396 | 441 | Â | Â | Â | 3406 |
4 | 5 | 463 | 423 | 6 | 466 | 428 | 7 | 452 | 432 | 8 | 434 | 411 | 9 | 439 | 416 | 4364 |
5 | 4 | 443 | 446 | 5 | 446 | 453 | 6 | 448 | 454 | 7 | 414 | 427 | 8 | 408 | 421 | 4360 |
6 | Â | Â | Â | 4 | 469 | 472 | 5 | 463 | 471 | 6 | 457 | 468 | 7 | 435 | 454 | 3689 |
7 | Â | Â | Â | Â | Â | Â | 4 | 462 | 465 | 5 | 460 | 466 | 6 | 456 | 463 | 2772 |
8 | Â | Â | Â | Â | Â | Â | Â | Â | Â | 4 | 457 | 426 | 5 | 461 | 434 | 1778 |
Total | Â | 2259 | 2204 | Â | 2713 | 2674 | Â | 2716 | 2673 | Â | 2618 | 2639 | Â | 2199 | 2188 | 24,883 |