| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 6 | 
                                                                 
                                    
                                    0.9%
                                 
                                                             | 
                                                        
                    
| -7 | Does not apply is a floor in a building (spontaneous) | 7 | 
                                                                 
                                    
                                    1%
                                 
                                                             | 
                                                        
                    
| 0 | 647 | 
                                                                 
                                    
                                    95.3%
                                 
                                                             | 
                                                        
                    |
| 1 | 2 | 
                                                                 
                                    
                                    0.3%
                                 
                                                             | 
                                                        
                    |
| 15 | 1 | 
                                                                 
                                    
                                    0.1%
                                 
                                                             | 
                                                        
                    |
| 30 | 1 | 
                                                                 
                                    
                                    0.1%
                                 
                                                             | 
                                                        
                    |
| 50 | 1 | 
                                                                 
                                    
                                    0.1%
                                 
                                                             | 
                                                        
                    |
| 80 | 1 | 
                                                                 
                                    
                                    0.1%
                                 
                                                             | 
                                                        
                    |
| 100 | 13 | 
                                                                 
                                    
                                    1.9%
                                 
                                                             | 
                                                        
                    |
| Sysmiss | 276 |