| Value | Category | Cases | |
|---|---|---|---|
| 1 | 1 year or less than | 10 | 
                                    
                                    23.8%
                                 | 
| 2 | 1 to 5 years | 18 | 
                                    
                                    42.9%
                                 | 
| 3 | More than 5 years | 14 | 
                                    
                                    33.3%
                                 | 
| Sysmiss | 958 |