| Value | Category | Cases | |
|---|---|---|---|
| -1 | Missing | 2 | 
                                    
                                    0%
                                 | 
| 0 | Never | 11991 | 
                                    
                                    47.2%
                                 | 
| 1 | Just once or twice | 4005 | 
                                    
                                    15.8%
                                 | 
| 2 | Several times | 4957 | 
                                    
                                    19.5%
                                 | 
| 3 | Many times | 3239 | 
                                    
                                    12.8%
                                 | 
| 4 | Always | 1150 | 
                                    
                                    4.5%
                                 | 
| 9 | Don't Know | 53 | 
                                    
                                    0.2%
                                 | 
| 998 | Refused | 0 | 
                                    
                                    0%
                                 |