| Value | Category | 
                                    
                    
                        | 1 | almost all of them | 
                                    
                    
                        | 2 | about half | 
                                    
                    
                        | 3 | about one quarter | 
                                    
                    
                        | 4 | less than one quarter | 
                                    
                    
                        | 5 | none of them | 
                                    
                    
                        | 9 | no answer | 
                            
            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.