| Value | Category | Cases | |
|---|---|---|---|
| 1 | Always available | 144 | 
                                    
                                    60%
                                 | 
| 2 | Sometime available | 94 | 
                                    
                                    39.2%
                                 | 
| 3 | Never available | 2 | 
                                    
                                    0.8%
                                 | 
| Sysmiss | 103 |