| Value | Category | Cases | |
|---|---|---|---|
| -1 | Missing | 1 |
0.1%
|
| 0 | Not at all effective | 380 |
31.8%
|
| 1 | Not very effective | 160 |
13.4%
|
| 2 | Somewhat effective | 239 |
20%
|
| 3 | Very effective | 231 |
19.3%
|
| 9 | Don't know | 185 |
15.5%
|
| 98 | Refused | 0 |
0%
|