| Value | Category | Cases | |
|---|---|---|---|
| 1982 | 4 |
14.8%
|
|
| 1983 | 7 |
25.9%
|
|
| 1984 | 3 |
11.1%
|
|
| 1985 | 3 |
11.1%
|
|
| 1986 | 3 |
11.1%
|
|
| 1987 | 4 |
14.8%
|
|
| 1988 | 3 |
11.1%
|
|
| Sysmiss | 72 |