| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 17 | 
                                                                 
                                    
                                    6.4%
                                 
                                                             | 
                                                        
                    
| 1 | Never | 62 | 
                                                                 
                                    
                                    23.4%
                                 
                                                             | 
                                                        
                    
| 2 | Once a week | 119 | 
                                                                 
                                    
                                    44.9%
                                 
                                                             | 
                                                        
                    
| 3 | Between 2 and 4 times a week | 52 | 
                                                                 
                                    
                                    19.6%
                                 
                                                             | 
                                                        
                    
| 4 | Daily | 13 | 
                                                                 
                                    
                                    4.9%
                                 
                                                             | 
                                                        
                    
| 5 | More than once a day | 2 | 
                                                                 
                                    
                                    0.8%
                                 
                                                             | 
                                                        
                    
| Sysmiss | 507 |