| Value | Category | Cases | |
|---|---|---|---|
| -1 | Missing | 0 | 
                                    
                                    0%
                                 | 
| 0 | Never | 2200 | 
                                    
                                    91.7%
                                 | 
| 1 | Once or twice | 102 | 
                                    
                                    4.3%
                                 | 
| 2 | Several times | 80 | 
                                    
                                    3.3%
                                 | 
| 3 | Many times | 14 | 
                                    
                                    0.6%
                                 | 
| 8 | Refused | 0 | 
                                    
                                    0%
                                 | 
| 9 | Don't know | 4 | 
                                    
                                    0.2%
                                 |