| Value | Category | Cases | |
|---|---|---|---|
| 1 | 13 | 9 |
2.6%
|
| 2 | 14 | 7 |
2%
|
| 3 | 15 | 7 |
2%
|
| 4 | 16 | 3 |
0.9%
|
| 5 | 17 | 4 |
1.2%
|
| 6 | 18 | 12 |
3.5%
|
| 7 | 19 | 3 |
0.9%
|
| 8 | 20 | 1 |
0.3%
|
| 9 | 21 | 2 |
0.6%
|
| Missing value | 297 |
86.1%
|