| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 2 | 
                                                                 
                                    
                                    0.3%
                                 
                                                             | 
                                                        
                    
| -7 | Does not apply | 25 | 
                                                                 
                                    
                                    4.3%
                                 
                                                             | 
                                                        
                    
| 0 | No obstacle | 476 | 
                                                                 
                                    
                                    82.1%
                                 
                                                             | 
                                                        
                    
| 1 | Minor obstacle | 27 | 
                                                                 
                                    
                                    4.7%
                                 
                                                             | 
                                                        
                    
| 2 | Moderate obstacle | 28 | 
                                                                 
                                    
                                    4.8%
                                 
                                                             | 
                                                        
                    
| 3 | Major obstacle | 19 | 
                                                                 
                                    
                                    3.3%
                                 
                                                             | 
                                                        
                    
| 4 | Very severe obstacle | 3 | 
                                                                 
                                    
                                    0.5%
                                 
                                                             | 
                                                        
                    
| Sysmiss | 1 |