| Value | 
                    Category | 
                                                                            
                                    
                    
                        | 00 | 
                        NIU (not in universe)  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 10 | 
                        None  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 20 | 
                        Electricity  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 30 | 
                        Petroleum gas, unspecified  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 31 | 
                        Gas -- piped/utility  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 32 | 
                        Gas -- tanked or bottled  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 33 | 
                        Propane  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 34 | 
                        Liquefied petroleum gas  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 35 | 
                        Gas -- piped and bottled  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 40 | 
                        Petroleum liquid  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 41 | 
                        Oil, kerosene, and other liquid fuels  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 42 | 
                        Kerosene/paraffin  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 43 | 
                        Kerosene or oil  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 44 | 
                        Kerosene or gasoline  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 45 | 
                        Gasoline  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 46 | 
                        Cocinol  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 47 | 
                        Diesel  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 50 | 
                        Wood, coal, and other solid fuels  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 51 | 
                        Wood and other plant fuels  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 52 | 
                        Non-wood plant materials  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 53 | 
                        Coal or charcoal  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 54 | 
                        Charcoal  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 55 | 
                        Coal  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 56 | 
                        Wood or charcoal  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 60 | 
                        Multiple fuels  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 61 | 
                        Bottled gas and wood  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 62 | 
                        Propane and electricity  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 63 | 
                        Propane, kerosene, and electricity  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 64 | 
                        Propane and kerosene  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 65 | 
                        Kerosene and electrictiy  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 66 | 
                        Other combinations  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 70 | 
                        Other  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 71 | 
                        Alcohol  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 72 | 
                        Biogas  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 73 | 
                        Discarded or waste material  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 74 | 
                        Dung/manure  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 75 | 
                        Other combined organic waste materials  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 76 | 
                        Solar energy  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 77 | 
                        Candle  | 
                        
                            
                        
                        
                        
                        
                            
                    
                                    
                    
                        | 99 | 
                        Unknown/missing  | 
                        
                            
                        
                        
                        
                        
                            
                    
                            
            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.