| Value | Category | 
                                    
                    
                        | -999999999 | missing | 
                                    
                    
                        | 1 | Much less | 
                                    
                    
                        | 2 | Less | 
                                    
                    
                        | 3 | About the same | 
                                    
                    
                        | 4 | Greater | 
                                    
                    
                        | 5 | Much greater | 
                            
            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.