| Value | Category | Cases | |
|---|---|---|---|
| -1 | Missing | 4 |
0.3%
|
| 0 | Not at all effective | 126 |
10.5%
|
| 1 | Not very effective | 304 |
25.3%
|
| 2 | Somewhat effective | 369 |
30.8%
|
| 3 | Very effective | 208 |
17.3%
|
| 9 | Don't know | 189 |
15.8%
|
| 98 | Refused | 0 |
0%
|