| Value | Category | Cases | |
|---|---|---|---|
| 1 | None | 3244 | 
                                                                 
                                    
                                    38.3%
                                 
                                                             | 
                                                        
                    
| 2 | Only non-electric | 2784 | 
                                                                 
                                    
                                    32.8%
                                 
                                                             | 
                                                        
                    
| 3 | Electric, or both electric and non-electric | 2451 | 
                                                                 
                                    
                                    28.9%
                                 
                                                             | 
                                                        
                    
| Sysmiss | 92 |