| Value | Category | Cases | |
|---|---|---|---|
| 1 | Not effective at all | 1 |
0.6%
|
| 10 | Very effective | 6 |
3.4%
|
| 11 | Don't know | 27 |
15.2%
|
| -99 | 5 |
2.8%
|
|
| 2 | 7 |
3.9%
|
|
| 3 | 6 |
3.4%
|
|
| 4 | 12 |
6.7%
|
|
| 5 | 26 |
14.6%
|
|
| 6 | 26 |
14.6%
|
|
| 7 | 26 |
14.6%
|
|
| 8 | 23 |
12.9%
|
|
| 9 | 13 |
7.3%
|
|
| Sysmiss | 13 |