| Value | Category | Cases | |
|---|---|---|---|
| -1 | Missing | 0 | 
                                    
                                    0%
                                 | 
| 0 | Never | 613 | 
                                    
                                    51.1%
                                 | 
| 1 | Once or twice | 249 | 
                                    
                                    20.8%
                                 | 
| 2 | Several times | 220 | 
                                    
                                    18.3%
                                 | 
| 3 | Many times | 109 | 
                                    
                                    9.1%
                                 | 
| 8 | Refused | 2 | 
                                    
                                    0.2%
                                 | 
| 9 | Don't know | 7 | 
                                    
                                    0.6%
                                 |