| Value | Category | Cases | |
|---|---|---|---|
| 1995 | 1 | 
                                    
                                    0.2%
                                 | |
| 2000 | 4 | 
                                    
                                    0.7%
                                 | |
| 2001 | 4 | 
                                    
                                    0.7%
                                 | |
| 2002 | 2 | 
                                    
                                    0.4%
                                 | |
| 2003 | 8 | 
                                    
                                    1.4%
                                 | |
| 2004 | 17 | 
                                    
                                    3.1%
                                 | |
| 2005 | 24 | 
                                    
                                    4.3%
                                 | |
| 2006 | 37 | 
                                    
                                    6.7%
                                 | |
| 2007 | 87 | 
                                    
                                    15.6%
                                 | |
| 2008 | 148 | 
                                    
                                    26.6%
                                 | |
| 2009 | 198 | 
                                    
                                    35.6%
                                 | |
| 2010 | 24 | 
                                    
                                    4.3%
                                 | |
| 2011 | 2 | 
                                    
                                    0.4%
                                 | |
| Sysmiss | 9956 |