| Value | Category | Cases | |
|---|---|---|---|
| 1973 | 1 |
0.2%
|
|
| 1983 | 1 |
0.2%
|
|
| 1986 | 2 |
0.3%
|
|
| 1987 | 2 |
0.3%
|
|
| 1988 | 8 |
1.3%
|
|
| 1989 | 8 |
1.3%
|
|
| 1990 | 7 |
1.1%
|
|
| 1991 | 35 |
5.5%
|
|
| 1992 | 54 |
8.5%
|
|
| 1993 | 43 |
6.7%
|
|
| 1994 | 53 |
8.3%
|
|
| 1995 | 43 |
6.7%
|
|
| 1996 | 31 |
4.9%
|
|
| 1997 | 50 |
7.8%
|
|
| 1998 | 50 |
7.8%
|
|
| 1999 | 43 |
6.7%
|
|
| 2000 | 81 |
12.7%
|
|
| 2001 | 57 |
8.9%
|
|
| 2002 | 20 |
3.1%
|
|
| 2003 | 26 |
4.1%
|
|
| 2004 | 11 |
1.7%
|
|
| 2005 | 11 |
1.7%
|
|
| 2006 | 1 |
0.2%
|
|
| 2007 | 1 |
0.2%
|
|
| Sysmiss | 1 |