| Value | Category | Cases | |
|---|---|---|---|
| -99 | 4 | 
                                                                 
                                    
                                    1.5%
                                 
                                                             | 
                                                        
                    |
| 1 | Every few days | 4 | 
                                                                 
                                    
                                    1.5%
                                 
                                                             | 
                                                        
                    
| 2 | Every few weeks | 39 | 
                                                                 
                                    
                                    14.9%
                                 
                                                             | 
                                                        
                    
| 3 | Every few months | 104 | 
                                                                 
                                    
                                    39.8%
                                 
                                                             | 
                                                        
                    
| 4 | Not at all | 60 | 
                                                                 
                                    
                                    23%
                                 
                                                             | 
                                                        
                    
| Sysmiss | 50 | 
                                                                 
                                    
                                    19.2%
                                 
                                                             |