| Value | Category | Cases | |
|---|---|---|---|
| 1980 | 1 |
0.7%
|
|
| 1987 | 1 |
0.7%
|
|
| 1989 | 1 |
0.7%
|
|
| 1990 | 2 |
1.3%
|
|
| 1992 | 1 |
0.7%
|
|
| 1993 | 1 |
0.7%
|
|
| 1994 | 2 |
1.3%
|
|
| 1995 | 1 |
0.7%
|
|
| 1996 | 3 |
2%
|
|
| 1997 | 2 |
1.3%
|
|
| 1998 | 5 |
3.3%
|
|
| 1999 | 5 |
3.3%
|
|
| 2000 | 9 |
6%
|
|
| 2001 | 4 |
2.6%
|
|
| 2002 | 4 |
2.6%
|
|
| 2003 | 12 |
7.9%
|
|
| 2004 | 13 |
8.6%
|
|
| 2005 | 13 |
8.6%
|
|
| 2006 | 24 |
15.9%
|
|
| 2007 | 19 |
12.6%
|
|
| 2008 | 28 |
18.5%
|
|
| Sysmiss | 295 |