| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 237 | 
                                                                 
                                    
                                    61.4%
                                 
                                                             | 
                                                        
                    
| 1990 | 3 | 
                                                                 
                                    
                                    0.8%
                                 
                                                             | 
                                                        
                    |
| 2000 | 8 | 
                                                                 
                                    
                                    2.1%
                                 
                                                             | 
                                                        
                    |
| 2001 | 1 | 
                                                                 
                                    
                                    0.3%
                                 
                                                             | 
                                                        
                    |
| 2005 | 4 | 
                                                                 
                                    
                                    1%
                                 
                                                             | 
                                                        
                    |
| 2008 | 3 | 
                                                                 
                                    
                                    0.8%
                                 
                                                             | 
                                                        
                    |
| 2009 | 5 | 
                                                                 
                                    
                                    1.3%
                                 
                                                             | 
                                                        
                    |
| 2010 | 4 | 
                                                                 
                                    
                                    1%
                                 
                                                             | 
                                                        
                    |
| 2011 | 1 | 
                                                                 
                                    
                                    0.3%
                                 
                                                             | 
                                                        
                    |
| 2012 | 7 | 
                                                                 
                                    
                                    1.8%
                                 
                                                             | 
                                                        
                    |
| 2013 | 6 | 
                                                                 
                                    
                                    1.6%
                                 
                                                             | 
                                                        
                    |
| 2014 | 18 | 
                                                                 
                                    
                                    4.7%
                                 
                                                             | 
                                                        
                    |
| 2015 | 15 | 
                                                                 
                                    
                                    3.9%
                                 
                                                             | 
                                                        
                    |
| 2016 | 8 | 
                                                                 
                                    
                                    2.1%
                                 
                                                             | 
                                                        
                    |
| 2017 | 11 | 
                                                                 
                                    
                                    2.8%
                                 
                                                             | 
                                                        
                    |
| 2018 | 24 | 
                                                                 
                                    
                                    6.2%
                                 
                                                             | 
                                                        
                    |
| 2019 | 18 | 
                                                                 
                                    
                                    4.7%
                                 
                                                             | 
                                                        
                    |
| 2020 | 9 | 
                                                                 
                                    
                                    2.3%
                                 
                                                             | 
                                                        
                    |
| 2021 | 2 | 
                                                                 
                                    
                                    0.5%
                                 
                                                             | 
                                                        
                    |
| 2022 | 2 | 
                                                                 
                                    
                                    0.5%
                                 
                                                             | 
                                                        
                    |
| Sysmiss | 10286 |