| Value | Category | Cases | |
|---|---|---|---|
| -1 | Missing | 2 |
0.2%
|
| 0 | Not at all effective | 49 |
4.1%
|
| 1 | Not very effective | 153 |
12.8%
|
| 2 | Somewhat effective | 497 |
41.4%
|
| 3 | Very effective | 363 |
30.3%
|
| 9 | Don't know | 136 |
11.3%
|
| 98 | Refused | 0 |
0%
|