| Value | Category | Cases | |
|---|---|---|---|
| 1980 | 2 |
1.2%
|
|
| 1987 | 1 |
0.6%
|
|
| 1990 | 1 |
0.6%
|
|
| 1992 | 4 |
2.4%
|
|
| 1993 | 2 |
1.2%
|
|
| 1994 | 1 |
0.6%
|
|
| 1995 | 3 |
1.8%
|
|
| 1998 | 3 |
1.8%
|
|
| 2000 | 12 |
7.3%
|
|
| 2001 | 4 |
2.4%
|
|
| 2002 | 8 |
4.8%
|
|
| 2003 | 2 |
1.2%
|
|
| 2004 | 11 |
6.7%
|
|
| 2005 | 20 |
12.1%
|
|
| 2006 | 17 |
10.3%
|
|
| 2007 | 31 |
18.8%
|
|
| 2008 | 42 |
25.5%
|
|
| 9999 | 1 |
0.6%
|
|
| Sysmiss | 281 |