| Value | Category | Cases | |
|---|---|---|---|
| -99 | 56 | 
                                                                 
                                    
                                    14.2%
                                 
                                                             | 
                                                        
                    |
| 1 | Every few days | 15 | 
                                                                 
                                    
                                    3.8%
                                 
                                                             | 
                                                        
                    
| 2 | Every few weeks | 16 | 
                                                                 
                                    
                                    4.1%
                                 
                                                             | 
                                                        
                    
| 3 | Every few months | 87 | 
                                                                 
                                    
                                    22%
                                 
                                                             | 
                                                        
                    
| 4 | Not at all | 140 | 
                                                                 
                                    
                                    35.4%
                                 
                                                             | 
                                                        
                    
| Sysmiss | 81 | 
                                                                 
                                    
                                    20.5%
                                 
                                                             |