| Value | 
                    Category | 
                                                                            
                                    
                    
                        | 0 | 
                          | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 1 | 
                        Yes  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 2 | 
                        No  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 98 | 
                          | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 99 | 
                          | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 1987 | 
                          | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 1991 | 
                          | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 1992 | 
                          | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 1993 | 
                          | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 1994 | 
                          | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 1995 | 
                          | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 1996 | 
                          | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 1997 | 
                          | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 1998 | 
                          | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 1999 | 
                          | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 2000 | 
                          | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 2001 | 
                          | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 2002 | 
                          | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 9999 | 
                          | 
                        
                            
                        
                        
                        
                        
                            
                    
                            
            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.