| Value | Category | Cases | |
|---|---|---|---|
| -1 | Missing | 3 |
0.3%
|
| 0 | Not at all effective | 88 |
7.3%
|
| 1 | Not very effective | 251 |
20.9%
|
| 2 | Somewhat effective | 454 |
37.9%
|
| 3 | Very effective | 343 |
28.6%
|
| 9 | Don't know | 60 |
5%
|
| 98 | Refused | 0 |
0%
|