| Value | Category | Cases | |
|---|---|---|---|
| 2002 | 1 | 
                                    
                                    0.6%
                                 | |
| 2004 | 6 | 
                                    
                                    3.5%
                                 | |
| 2005 | 11 | 
                                    
                                    6.4%
                                 | |
| 2006 | 12 | 
                                    
                                    7%
                                 | |
| 2007 | 19 | 
                                    
                                    11.1%
                                 | |
| 2008 | 47 | 
                                    
                                    27.5%
                                 | |
| 2009 | 64 | 
                                    
                                    37.4%
                                 | |
| 2010 | 8 | 
                                    
                                    4.7%
                                 | |
| 2011 | 3 | 
                                    
                                    1.8%
                                 | |
| Sysmiss | 22 |