| Value | Category | Cases | |
|---|---|---|---|
| -99 | 53 | 
                                                                 
                                    
                                    13.4%
                                 
                                                             | 
                                                        
                    |
| 1 | Every few days | 17 | 
                                                                 
                                    
                                    4.3%
                                 
                                                             | 
                                                        
                    
| 2 | Every few weeks | 27 | 
                                                                 
                                    
                                    6.8%
                                 
                                                             | 
                                                        
                    
| 3 | Every few months | 138 | 
                                                                 
                                    
                                    34.9%
                                 
                                                             | 
                                                        
                    
| 4 | Not at all | 79 | 
                                                                 
                                    
                                    20%
                                 
                                                             | 
                                                        
                    
| Sysmiss | 81 | 
                                                                 
                                    
                                    20.5%
                                 
                                                             |