| Value | Category | Cases | |
|---|---|---|---|
| 2017 | 7 | 
                                    
                                    0.1%
                                 | |
| 2018 | 415 | 
                                    
                                    6.5%
                                 | |
| 2019 | 949 | 
                                    
                                    14.8%
                                 | |
| 2020 | 6 | 
                                    
                                    0.1%
                                 | |
| 9999 | NO RESPONSE | 4 | 
                                    
                                    0.1%
                                 | 
| Sysmiss | 5013 | 
                                    
                                    78.4%
                                 |