| Value | Category | 
                                    
                    
                        | 1 | Electricity | 
                                    
                    
                        | 2 | Natural gas | 
                                    
                    
                        | 3 | Biogas | 
                                    
                    
                        | 4 | Kerosene | 
                                    
                    
                        | 5 | Charcoal | 
                                    
                    
                        | 6 | Vegetable coal | 
                                    
                    
                        | 7 | Wood | 
                                    
                    
                        | 8 | Dung | 
                                    
                    
                        | 96 | Other | 
                            
            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.