| Value | Category | Cases | |
|---|---|---|---|
| -1 | Missing | 0 | 
                                    
                                    0%
                                 | 
| 0 | Never | 2030 | 
                                    
                                    84.6%
                                 | 
| 1 | Just once or twice | 194 | 
                                    
                                    8.1%
                                 | 
| 2 | Several times | 114 | 
                                    
                                    4.8%
                                 | 
| 3 | Many times | 39 | 
                                    
                                    1.6%
                                 | 
| 4 | Always | 15 | 
                                    
                                    0.6%
                                 | 
| 8 | Refused | 4 | 
                                    
                                    0.2%
                                 | 
| 9 | Don't know | 4 | 
                                    
                                    0.2%
                                 |