| Value | Category | Cases | |
|---|---|---|---|
| 99 | Missing | 0 |
0%
|
| 1984 | 1 |
2%
|
|
| 1988 | 34 |
66.7%
|
|
| 1989 | 4 |
7.8%
|
|
| 1991 | 2 |
3.9%
|
|
| 1992 | 1 |
2%
|
|
| 1994 | 9 |
17.6%
|
|
| Sysmiss | 1674 |