| Value | Category | Cases | |
|---|---|---|---|
| 2006 | 2 | 
                                    
                                    13.3%
                                 | |
| 2007 | 3 | 
                                    
                                    20%
                                 | |
| 2008 | 4 | 
                                    
                                    26.7%
                                 | |
| 2009 | 6 | 
                                    
                                    40%
                                 | |
| Sysmiss | 126 |