| Value | Category | 
                                    
                    
                        | -9 | Don't know | 
                                    
                    
                        | -7 | Does not apply | 
                                    
                    
                        | 0 | No Obstacle | 
                                    
                    
                        | 1 | Minor Obstacle | 
                                    
                    
                        | 2 | Moderate Obstacle | 
                                    
                    
                        | 3 | Major Obstacle | 
                                    
                    
                        | 4 | Very Severe Obstacle | 
                                    
                    
                        | Sysmiss |  | 
                            
            Warning: these figures indicate the number of cases found in the data file. They cannot be interpreted as summary statistics of the population of interest.