| Value | Category | 
                                    
                    
                        | 0 | 0 PPM (no iodine) | 
                                    
                    
                        | 7 | Below 15 PPM | 
                                    
                    
                        | 15 | 15 PPM and above | 
                                    
                    
                        | 30 | 30 PPM | 
                                    
                    
                        | 994 | Salt not tested | 
                                    
                    
                        | 995 | No salt in household | 
                            
            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.