| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 1 | 
                                                                 
                                    
                                    3.2%
                                 
                                                             | 
                                                        
                    
| 1 | Annually | 4 | 
                                                                 
                                    
                                    12.9%
                                 
                                                             | 
                                                        
                    
| 2 | Biannually/Every six months | 2 | 
                                                                 
                                    
                                    6.5%
                                 
                                                             | 
                                                        
                    
| 3 | Quarterly | 12 | 
                                                                 
                                    
                                    38.7%
                                 
                                                             | 
                                                        
                    
| 4 | Monthly | 11 | 
                                                                 
                                    
                                    35.5%
                                 
                                                             | 
                                                        
                    
| 5 | Weekly | 1 | 
                                                                 
                                    
                                    3.2%
                                 
                                                             | 
                                                        
                    
| 6 | Daily | 0 | 
                                                                 
                                    
                                    0%
                                 
                                                             | 
                                                        
                    
| 7 | Hourly | 0 | 
                                                                 
                                    
                                    0%
                                 
                                                             | 
                                                        
                    
| 8 | More than once in an hour | 0 | 
                                                                 
                                    
                                    0%
                                 
                                                             | 
                                                        
                    
| Sysmiss | 1415 |