| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 6 | 
                                                                 
                                    
                                    3.9%
                                 
                                                             | 
                                                        
                    
| -7 | Does not apply | 17 | 
                                                                 
                                    
                                    11.2%
                                 
                                                             | 
                                                        
                    
| 0 | No obstacle | 70 | 
                                                                 
                                    
                                    46.1%
                                 
                                                             | 
                                                        
                    
| 1 | Minor obstacle | 11 | 
                                                                 
                                    
                                    7.2%
                                 
                                                             | 
                                                        
                    
| 2 | Moderate obstacle | 26 | 
                                                                 
                                    
                                    17.1%
                                 
                                                             | 
                                                        
                    
| 3 | Major obstacle | 12 | 
                                                                 
                                    
                                    7.9%
                                 
                                                             | 
                                                        
                    
| 4 | Very severe obstacle | 10 | 
                                                                 
                                    
                                    6.6%
                                 
                                                             |