| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 2 | 
                                                                 
                                    
                                    1.4%
                                 
                                                             | 
                                                        
                    
| 1 | Never | 3 | 
                                                                 
                                    
                                    2.1%
                                 
                                                             | 
                                                        
                    
| 2 | Once a week | 24 | 
                                                                 
                                    
                                    16.6%
                                 
                                                             | 
                                                        
                    
| 3 | Between 2 and 4 times a week | 42 | 
                                                                 
                                    
                                    29%
                                 
                                                             | 
                                                        
                    
| 4 | Daily | 68 | 
                                                                 
                                    
                                    46.9%
                                 
                                                             | 
                                                        
                    
| 5 | More than once a day | 6 | 
                                                                 
                                    
                                    4.1%
                                 
                                                             | 
                                                        
                    
| Sysmiss | 436 |