| Value | Category | Cases | |
|---|---|---|---|
| 15 | 3516 |
42.8%
|
|
| 16 | 2709 |
32.9%
|
|
| 17 | 1364 |
16.6%
|
|
| 18 | 486 |
5.9%
|
|
| 19 | 122 |
1.5%
|
|
| 20 | 26 |
0.3%
|
|
| 98 | Don't know | 0 |
0%
|
| 99 | Refused | 0 |
0%
|