| Value | Category | 
                                    
                    
                        | 1 | Completed | 
                                    
                    
                        | 2 | Primarily completed, usable | 
                                    
                    
                        | 3 | Primarily completed, unusable | 
                                    
                    
                        | 4 | Not completed | 
                                    
                    
                        | 5 | Ineligible | 
                            
            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.