| Value | Category | 
                                    
                    
                        | 1 | Up to 10 minutes | 
                                    
                    
                        | 2 | 10 to 30 minutes | 
                                    
                    
                        | 3 | From 30 minutes to 1 hour | 
                                    
                    
                        | 4 | From 1:00 to 2:00 | 
                                    
                    
                        | 5 | 2 hours or more | 
                                    
                    
                        | 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.