| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 4 | 
                                    
                                    1%
                                 | 
| -7 | Does not apply | 4 | 
                                    
                                    1%
                                 | 
| 0 | No obstacle | 195 | 
                                    
                                    47.7%
                                 | 
| 1 | Minor obstacle | 74 | 
                                    
                                    18.1%
                                 | 
| 2 | Moderate obstacle | 100 | 
                                    
                                    24.4%
                                 | 
| 3 | Major obstacle | 24 | 
                                    
                                    5.9%
                                 | 
| 4 | Very severe obstacle | 8 | 
                                    
                                    2%
                                 | 
| Sysmiss | 546 |