| Value | Category | 
                                    
                    
                        | 1 | very much worse | 
                                    
                    
                        | 2 | much worse | 
                                    
                    
                        | 3 | worse | 
                                    
                    
                        | 4 | equal | 
                                    
                    
                        | 5 | better | 
                                    
                    
                        | 6 | much better | 
                                    
                    
                        | 7 | very much better | 
                            
            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.