| Value | Category | Cases | |
|---|---|---|---|
| -1 | Missing | 1 |
0.1%
|
| 0 | Not at all effective | 176 |
14.7%
|
| 1 | Not very effective | 247 |
20.6%
|
| 2 | Somewhat effective | 383 |
31.9%
|
| 3 | Very effective | 385 |
32.1%
|
| 9 | Don't know | 7 |
0.6%
|
| 98 | Refused | 0 |
0%
|