| Value | Category | Cases | |
|---|---|---|---|
| -1 | Missing | 0 |
0%
|
| 0 | Not at all effective | 41 |
3.4%
|
| 1 | Not very effective | 75 |
6.3%
|
| 2 | Somewhat effective | 288 |
24.2%
|
| 3 | Very effective | 714 |
59.9%
|
| 8 | Refused | 0 |
0%
|
| 9 | Don't know | 73 |
6.1%
|