| Value | Category | 
                                    
                    
                        | 0 |  | 
                                    
                    
                        | 1 |  | 
                                    
                    
                        | 5 |  | 
                                    
                    
                        | 12 |  | 
                                    
                    
                        | 13 |  | 
                                    
                    
                        | 14 |  | 
                                    
                    
                        | 15 |  | 
                                    
                    
                        | 17 |  | 
                                    
                    
                        | 19 |  | 
                                    
                    
                        | 20 |  | 
                                    
                    
                        | 22 |  | 
                                    
                    
                        | 23 |  | 
                                    
                    
                        | 24 |  | 
                                    
                    
                        | 25 |  | 
                                    
                    
                        | 30 |  | 
                                    
                    
                        | 36 |  | 
                                    
                    
                        | 45 |  | 
                                    
                    
                        | 48 |  | 
                                    
                    
                        | 50 |  | 
                                    
                    
                        | 77 | More than 3 days | 
                                    
                    
                        | 88 | Had no labor | 
                                    
                    
                        | 99 | Don't remember | 
                                    
                    
                        | 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.