| Value | 
                    Category | 
                                                                            
                                    
                    
                        | 0 | 
                        Not given  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 2013 | 
                          | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 4444 | 
                        Marked on card  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 9997 | 
                        Inconsistent  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 9998 | 
                        DK  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 9999 | 
                        Missing  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 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.