| Value | Category | Cases | |
|---|---|---|---|
| 2002 | 18 | 
                                                                 
                                    
                                    20.7%
                                 
                                                             | 
                                                        
                    |
| 2003 | 9 | 
                                                                 
                                    
                                    10.3%
                                 
                                                             | 
                                                        
                    |
| 2004 | 10 | 
                                                                 
                                    
                                    11.5%
                                 
                                                             | 
                                                        
                    |
| 2005 | 16 | 
                                                                 
                                    
                                    18.4%
                                 
                                                             | 
                                                        
                    |
| 2006 | 32 | 
                                                                 
                                    
                                    36.8%
                                 
                                                             | 
                                                        
                    |
| 2007 | 2 | 
                                                                 
                                    
                                    2.3%
                                 
                                                             | 
                                                        
                    |
| Sysmiss | 12 |