| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 5 | 
                                                                 
                                    
                                    26.3%
                                 
                                                             | 
                                                        
                    
| 2002 | 1 | 
                                                                 
                                    
                                    5.3%
                                 
                                                             | 
                                                        
                    |
| 2004 | 1 | 
                                                                 
                                    
                                    5.3%
                                 
                                                             | 
                                                        
                    |
| 2007 | 1 | 
                                                                 
                                    
                                    5.3%
                                 
                                                             | 
                                                        
                    |
| 2008 | 1 | 
                                                                 
                                    
                                    5.3%
                                 
                                                             | 
                                                        
                    |
| 2013 | 1 | 
                                                                 
                                    
                                    5.3%
                                 
                                                             | 
                                                        
                    |
| 2015 | 1 | 
                                                                 
                                    
                                    5.3%
                                 
                                                             | 
                                                        
                    |
| 2016 | 1 | 
                                                                 
                                    
                                    5.3%
                                 
                                                             | 
                                                        
                    |
| 2018 | 2 | 
                                                                 
                                    
                                    10.5%
                                 
                                                             | 
                                                        
                    |
| 2019 | 5 | 
                                                                 
                                    
                                    26.3%
                                 
                                                             | 
                                                        
                    |
| Sysmiss | 190 |