| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 | 
                                                                 
                                    
                                    0%
                                 
                                                             | 
                                                        
                    
| -7 | Does not apply | 14 | 
                                                                 
                                    
                                    3.8%
                                 
                                                             | 
                                                        
                    
| 0 | No obstacle | 133 | 
                                                                 
                                    
                                    36.5%
                                 
                                                             | 
                                                        
                    
| 1 | Minor obstacle | 62 | 
                                                                 
                                    
                                    17%
                                 
                                                             | 
                                                        
                    
| 2 | Moderate obstacle | 70 | 
                                                                 
                                    
                                    19.2%
                                 
                                                             | 
                                                        
                    
| 3 | Major obstacle | 61 | 
                                                                 
                                    
                                    16.8%
                                 
                                                             | 
                                                        
                    
| 4 | Very severe obstacle | 24 | 
                                                                 
                                    
                                    6.6%
                                 
                                                             |