| Value | Category | Cases | |
|---|---|---|---|
| -1 | Missing | 0 |
0%
|
| 0 | Not at all effective | 119 |
9.9%
|
| 1 | Not very effective | 150 |
12.5%
|
| 2 | Somewhat effective | 170 |
14.2%
|
| 3 | Very effective | 536 |
44.8%
|
| 9 | Don't know | 222 |
18.5%
|
| 998 | Refused | 0 |
0%
|