| Value | Category | Cases | |
|---|---|---|---|
| 1997 | 1 | 
                                                                 
                                    
                                    3.8%
                                 
                                                             | 
                                                        
                    |
| 2000 | 1 | 
                                                                 
                                    
                                    3.8%
                                 
                                                             | 
                                                        
                    |
| 2007 | 2 | 
                                                                 
                                    
                                    7.7%
                                 
                                                             | 
                                                        
                    |
| 2010 | 1 | 
                                                                 
                                    
                                    3.8%
                                 
                                                             | 
                                                        
                    |
| 2014 | 1 | 
                                                                 
                                    
                                    3.8%
                                 
                                                             | 
                                                        
                    |
| 2015 | 6 | 
                                                                 
                                    
                                    23.1%
                                 
                                                             | 
                                                        
                    |
| 2016 | 8 | 
                                                                 
                                    
                                    30.8%
                                 
                                                             | 
                                                        
                    |
| 2017 | 6 | 
                                                                 
                                    
                                    23.1%
                                 
                                                             | 
                                                        
                    |
| Sysmiss | 5332 |