| Value | Category | Cases | |
|---|---|---|---|
| -99 | 9 | 
                                    
                                    4.9%
                                 | |
| 1 | Every few days | 8 | 
                                    
                                    4.4%
                                 | 
| 2 | Every few weeks | 29 | 
                                    
                                    15.8%
                                 | 
| 3 | Every few months | 67 | 
                                    
                                    36.6%
                                 | 
| 4 | Not at all | 42 | 
                                    
                                    23%
                                 | 
| Sysmiss | 28 | 
                                    
                                    15.3%
                                 |