| Value | Category | Cases | |
|---|---|---|---|
| 1998 | 1 | 
                                    
                                    14.3%
                                 | |
| 2007 | 1 | 
                                    
                                    14.3%
                                 | |
| 2008 | 1 | 
                                    
                                    14.3%
                                 | |
| 2009 | 4 | 
                                    
                                    57.1%
                                 | |
| Sysmiss | 407 |