| Value | Category | Cases | |
|---|---|---|---|
| 1 | Everyday | 20 | 
                                
                                0.1%
                             | 
| 2 | Once a week | 7 | 
                                
                                0%
                             | 
| 3 | Once a month | 43 | 
                                
                                0.1%
                             | 
| 4 | Once a term | 801 | 
                                
                                2.3%
                             | 
| 5 | Once a year | 13837 | 
                                
                                39.3%
                             | 
| 6 | Unspecified | 1758 | 
                                
                                5%
                             | 
| 95 | Missing | 29 | 
                                
                                0.1%
                             | 
| 98 | Don't know | 24 | 
                                
                                0.1%
                             | 
| 99 | NA | 18670 | 
                                
                                53.1%
                             |