| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 3 | 
                                                                 
                                    
                                    0.5%
                                 
                                                             | 
                                                        
                    
| -7 | Does not apply | 10 | 
                                                                 
                                    
                                    1.7%
                                 
                                                             | 
                                                        
                    
| 0 | No obstacle | 201 | 
                                                                 
                                    
                                    34.7%
                                 
                                                             | 
                                                        
                    
| 1 | Minor obstacle | 36 | 
                                                                 
                                    
                                    6.2%
                                 
                                                             | 
                                                        
                    
| 2 | Moderate obstacle | 83 | 
                                                                 
                                    
                                    14.3%
                                 
                                                             | 
                                                        
                    
| 3 | Major obstacle | 147 | 
                                                                 
                                    
                                    25.3%
                                 
                                                             | 
                                                        
                    
| 4 | Very severe obstacle | 100 | 
                                                                 
                                    
                                    17.2%
                                 
                                                             | 
                                                        
                    
| Sysmiss | 1 |