| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 4 | 
                                                                 
                                    
                                    0.7%
                                 
                                                             | 
                                                        
                    
| -7 | Does not apply | 8 | 
                                                                 
                                    
                                    1.4%
                                 
                                                             | 
                                                        
                    
| 0 | No obstacle | 329 | 
                                                                 
                                    
                                    56.7%
                                 
                                                             | 
                                                        
                    
| 1 | Minor obstacle | 68 | 
                                                                 
                                    
                                    11.7%
                                 
                                                             | 
                                                        
                    
| 2 | Moderate obstacle | 63 | 
                                                                 
                                    
                                    10.9%
                                 
                                                             | 
                                                        
                    
| 3 | Major obstacle | 87 | 
                                                                 
                                    
                                    15%
                                 
                                                             | 
                                                        
                    
| 4 | Very severe obstacle | 21 | 
                                                                 
                                    
                                    3.6%
                                 
                                                             | 
                                                        
                    
| Sysmiss | 1 |