| Value | Category | Cases | |
|---|---|---|---|
| -1 | Missing | 0 | 
                                                                 
                                    
                                    0%
                                 
                                                             | 
                                                        
                    
| 1 | Impassable | 0 | 
                                                                 
                                    
                                    0%
                                 
                                                             | 
                                                        
                    
| 2 | Very poor | 0 | 
                                                                 
                                    
                                    0%
                                 
                                                             | 
                                                        
                    
| 3 | Poor | 55 | 
                                                                 
                                    
                                    4.7%
                                 
                                                             | 
                                                        
                    
| 4 | Fair | 236 | 
                                                                 
                                    
                                    20.1%
                                 
                                                             | 
                                                        
                    
| 5 | Good | 409 | 
                                                                 
                                    
                                    34.8%
                                 
                                                             | 
                                                        
                    
| 6 | Very good | 476 | 
                                                                 
                                    
                                    40.5%
                                 
                                                             |