| Value | Category | 
                                    
                    
                        | 1 | greater than 20 minutes | 
                                    
                    
                        | 2 | 11-20 minutes | 
                                    
                    
                        | 3 | 6-10 minutes | 
                                    
                    
                        | 4 | 5 min or less | 
                                    
                    
                        | 5 | never left unsupervised | 
                            
            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.