| Value | Category | Cases | |
|---|---|---|---|
| 777 | Don't Know | 0 |
0%
|
| 1991 | 3 |
3.3%
|
|
| 1992 | 36 |
39.6%
|
|
| 1993 | 29 |
31.9%
|
|
| 1994 | 23 |
25.3%
|
|
| Sysmiss | 5490 |