| Value | Category | Cases | |
|---|---|---|---|
| -1 | Missing | 1 |
0.1%
|
| 0 | Not at all effective | 87 |
7.3%
|
| 1 | Not very effective | 340 |
28.3%
|
| 2 | Somewhat effective | 436 |
36.3%
|
| 3 | Very effective | 221 |
18.4%
|
| 9 | Don't know | 115 |
9.6%
|
| 98 | Refused | 0 |
0%
|