| Value | Category | 
                                    
                    
                        | 1 | none trained | 
                                    
                    
                        | 2 | no materials | 
                                    
                    
                        | 3 | all have been trained | 
                                    
                    
                        | 4 | some have been trained | 
                                    
                    
                        | 5 | only one has been trained | 
                            
            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.