| Value | Category | Cases | |
|---|---|---|---|
| 1 | Less than 2 years | 422 | 
                                    
                                    33%
                                 | 
| 2 | 2 to 4 years | 506 | 
                                    
                                    39.6%
                                 | 
| 3 | More than 4 years | 351 | 
                                    
                                    27.4%
                                 | 
| 9 | Missing | 0 | 
                                    
                                    0%
                                 | 
| Sysmiss | 10871 |