| Value | Category | Cases | |
|---|---|---|---|
| 1 | Highly effective | 2471 |
12.7%
|
| 2 | Moderately effective | 10879 |
56%
|
| 3 | Ineffective | 3157 |
16.2%
|
| 4 | Don't know | 2921 |
15%
|