| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 25 | 
                                                                 
                                    
                                    1.7%
                                 
                                                             | 
                                                        
                    
| -7 | Does not apply | 60 | 
                                                                 
                                    
                                    4.2%
                                 
                                                             | 
                                                        
                    
| 0 | No obstacle | 696 | 
                                                                 
                                    
                                    48.6%
                                 
                                                             | 
                                                        
                    
| 1 | Minor obstacle | 202 | 
                                                                 
                                    
                                    14.1%
                                 
                                                             | 
                                                        
                    
| 2 | Moderate obstacle | 210 | 
                                                                 
                                    
                                    14.7%
                                 
                                                             | 
                                                        
                    
| 3 | Major obstacle | 168 | 
                                                                 
                                    
                                    11.7%
                                 
                                                             | 
                                                        
                    
| 4 | Very severe obstacle | 71 | 
                                                                 
                                    
                                    5%
                                 
                                                             |