| Value | Category | Cases | |
|---|---|---|---|
| -1 | Missing | 5 |
0.4%
|
| 0 | Not at all effective | 67 |
5.6%
|
| 1 | Not very effective | 221 |
18.4%
|
| 2 | Somewhat effective | 511 |
42.6%
|
| 3 | Very effective | 306 |
25.5%
|
| 9 | Don't know | 90 |
7.5%
|
| 98 | Refused | 0 |
0%
|