| Value | Category | Cases | |
|---|---|---|---|
| 1978 | 1 |
16.7%
|
|
| 1980 | 1 |
16.7%
|
|
| 1982 | 1 |
16.7%
|
|
| 1984 | 2 |
33.3%
|
|
| 1986 | 1 |
16.7%
|
|
| Sysmiss | 425 |