| Value | Category | Cases | |
|---|---|---|---|
| 1994 | 1 | 
                                    
                                    0.8%
                                 | |
| 1997 | 1 | 
                                    
                                    0.8%
                                 | |
| 1998 | 4 | 
                                    
                                    3.1%
                                 | |
| 2000 | 1 | 
                                    
                                    0.8%
                                 | |
| 2002 | 1 | 
                                    
                                    0.8%
                                 | |
| 2003 | 3 | 
                                    
                                    2.3%
                                 | |
| 2004 | 1 | 
                                    
                                    0.8%
                                 | |
| 2005 | 2 | 
                                    
                                    1.5%
                                 | |
| 2006 | 11 | 
                                    
                                    8.4%
                                 | |
| 2007 | 18 | 
                                    
                                    13.7%
                                 | |
| 2008 | 88 | 
                                    
                                    67.2%
                                 | |
| Sysmiss | 301 |