| Value | Category | Cases | |
|---|---|---|---|
| 1 | Less than an hour | 240 | 
                                                                 
                                    
                                    26.1%
                                 
                                                             | 
                                                        
                    
| 2 | Between one and three hours | 362 | 
                                                                 
                                    
                                    39.4%
                                 
                                                             | 
                                                        
                    
| 3 | More than three hours | 316 | 
                                                                 
                                    
                                    34.4%
                                 
                                                             | 
                                                        
                    
| Sysmiss | 8942 |