| Value | Category | Cases | |
|---|---|---|---|
| -1 | Missing | 8 |
0.7%
|
| 0 | Not at all effective | 50 |
4.2%
|
| 1 | Not very effective | 409 |
34.1%
|
| 2 | Somewhat effective | 454 |
37.9%
|
| 3 | Very effective | 262 |
21.9%
|
| 9 | Don't know | 16 |
1.3%
|
| 98 | Refused | 0 |
0%
|