| Value | Category | Cases | |
|---|---|---|---|
| 1 | Every few days | 6 | 
                                                                 
                                    
                                    2.1%
                                 
                                                             | 
                                                        
                    
| 2 | Every few weeks | 32 | 
                                                                 
                                    
                                    11.3%
                                 
                                                             | 
                                                        
                    
| 3 | Every few months | 131 | 
                                                                 
                                    
                                    46.1%
                                 
                                                             | 
                                                        
                    
| 4 | Not at all | 115 | 
                                                                 
                                    
                                    40.5%
                                 
                                                             | 
                                                        
                    
| Sysmiss | 91 |