| Value | Category | Cases | |
|---|---|---|---|
| 1968 | 1 |
0.1%
|
|
| 1969 | 13 |
1.2%
|
|
| 1970 | 21 |
2%
|
|
| 1971 | 11 |
1%
|
|
| 1972 | 14 |
1.3%
|
|
| 1973 | 16 |
1.5%
|
|
| 1974 | 13 |
1.2%
|
|
| 1975 | 10 |
1%
|
|
| 1976 | 12 |
1.1%
|
|
| 1977 | 14 |
1.3%
|
|
| 1978 | 16 |
1.5%
|
|
| 1979 | 17 |
1.6%
|
|
| 1980 | 16 |
1.5%
|
|
| 1981 | 23 |
2.2%
|
|
| 1982 | 21 |
2%
|
|
| 1983 | 17 |
1.6%
|
|
| 1984 | 22 |
2.1%
|
|
| 1985 | 23 |
2.2%
|
|
| 1986 | 28 |
2.7%
|
|
| 1987 | 19 |
1.8%
|
|
| 1988 | 24 |
2.3%
|
|
| 1989 | 19 |
1.8%
|
|
| 1990 | 25 |
2.4%
|
|
| 1991 | 21 |
2%
|
|
| 1992 | 18 |
1.7%
|
|
| 1993 | 22 |
2.1%
|
|
| 1994 | 24 |
2.3%
|
|
| 1995 | 25 |
2.4%
|
|
| 1996 | 20 |
1.9%
|
|
| 1997 | 27 |
2.6%
|
|
| 1998 | 34 |
3.2%
|
|
| 1999 | 22 |
2.1%
|
|
| 2000 | 36 |
3.4%
|
|
| 2001 | 28 |
2.7%
|
|
| 2002 | 17 |
1.6%
|
|
| 2003 | 20 |
1.9%
|
|
| 9998 | DK | 4 |
0.4%
|
| Sysmiss | 335 |
32%
|