| Value | Category | Cases | |
|---|---|---|---|
| 1952 | 1 |
2.9%
|
|
| 1970 | 1 |
2.9%
|
|
| 1974 | 2 |
5.9%
|
|
| 1975 | 1 |
2.9%
|
|
| 1977 | 1 |
2.9%
|
|
| 1978 | 1 |
2.9%
|
|
| 1979 | 1 |
2.9%
|
|
| 1980 | 5 |
14.7%
|
|
| 1982 | 1 |
2.9%
|
|
| 1983 | 1 |
2.9%
|
|
| 1984 | 1 |
2.9%
|
|
| 1986 | 2 |
5.9%
|
|
| 1989 | 2 |
5.9%
|
|
| 1990 | 6 |
17.6%
|
|
| 1994 | 2 |
5.9%
|
|
| 1995 | 2 |
5.9%
|
|
| 1996 | 1 |
2.9%
|
|
| 1997 | 2 |
5.9%
|
|
| 1998 | 1 |
2.9%
|
|
| Sysmiss | 866 |