| Value | Category | 
                                    
                    
                        | 1 | Small (between 5 and 19) | 
                                    
                    
                        | 2 | Medium (between 20 and 99) | 
                                    
                    
                        | 3 | Large (greather than 100) | 
                            
            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.