| Value | Category | Cases | |
|---|---|---|---|
| 1976 | 1 |
5.3%
|
|
| 1978 | 1 |
5.3%
|
|
| 1980 | 2 |
10.5%
|
|
| 1981 | 1 |
5.3%
|
|
| 1982 | 2 |
10.5%
|
|
| 1983 | 2 |
10.5%
|
|
| 1984 | 1 |
5.3%
|
|
| 1985 | 3 |
15.8%
|
|
| 1986 | 3 |
15.8%
|
|
| 1988 | 1 |
5.3%
|
|
| 1990 | 1 |
5.3%
|
|
| 1991 | 1 |
5.3%
|
|
| Sysmiss | 1412 |