| Value | Category | 
                                    
                    
                        | 1 | no display | 
                                    
                    
                        | 2 | disply but not age appropriate | 
                                    
                    
                        | 3 | display is small, damaged, or not at eye-level | 
                                    
                    
                        | 4 | large, approriate, visible display | 
                            
            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.