| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 177 | 
                                                                 
                                    
                                    6%
                                 
                                                             | 
                                                        
                    
| -7 | Does not apply | 339 | 
                                                                 
                                    
                                    11.5%
                                 
                                                             | 
                                                        
                    
| 0 | No obstacle | 1334 | 
                                                                 
                                    
                                    45.1%
                                 
                                                             | 
                                                        
                    
| 1 | Minor obstacle | 498 | 
                                                                 
                                    
                                    16.9%
                                 
                                                             | 
                                                        
                    
| 2 | Moderate obstacle | 433 | 
                                                                 
                                    
                                    14.7%
                                 
                                                             | 
                                                        
                    
| 3 | Major obstacle | 146 | 
                                                                 
                                    
                                    4.9%
                                 
                                                             | 
                                                        
                    
| 4 | Very severe obstacle | 28 | 
                                                                 
                                    
                                    0.9%
                                 
                                                             |