| Value | Category | Cases | |
|---|---|---|---|
| -99 | 4 | 
                                                                 
                                    
                                    1%
                                 
                                                             | 
                                                        
                    |
| 1 | Every few days | 28 | 
                                                                 
                                    
                                    7.1%
                                 
                                                             | 
                                                        
                    
| 2 | Every few weeks | 44 | 
                                                                 
                                    
                                    11.1%
                                 
                                                             | 
                                                        
                    
| 3 | Every few months | 174 | 
                                                                 
                                    
                                    44.1%
                                 
                                                             | 
                                                        
                    
| 4 | Not at all | 64 | 
                                                                 
                                    
                                    16.2%
                                 
                                                             | 
                                                        
                    
| Sysmiss | 81 | 
                                                                 
                                    
                                    20.5%
                                 
                                                             |