| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know (spontaneous) | 0 | 
                                    
                                    0%
                                 | 
| 1 | Annually | 0 | 
                                    
                                    0%
                                 | 
| 2 | Biannually/Every six months | 2 | 
                                    
                                    20%
                                 | 
| 3 | Quarterly | 2 | 
                                    
                                    20%
                                 | 
| 4 | Monthly | 4 | 
                                    
                                    40%
                                 | 
| 5 | Weekly | 2 | 
                                    
                                    20%
                                 | 
| 6 | Daily | 0 | 
                                    
                                    0%
                                 | 
| 7 | Hourly | 0 | 
                                    
                                    0%
                                 | 
| 8 | More than once in an hour | 0 | 
                                    
                                    0%
                                 | 
| Sysmiss | 750 |