| Value | Category | 
                                    
                    
                        | 0 | Not willing | 
                                    
                    
                        | 1 | Easily | 
                                    
                    
                        | 2 | With a little difficulty | 
                                    
                    
                        | 3 | With a lot of difficulty | 
                                    
                    
                        | 4 | Not at all | 
                                    
                    
                        | 9 | Don't know | 
                            
            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.