| Value | Category | Cases | |
|---|---|---|---|
| 1 | Every week | 1930 | 
                                    
                                    52.4%
                                 | 
| 2 | 1-3 times a month | 1053 | 
                                    
                                    28.6%
                                 | 
| 3 | 1-2 times per term | 216 | 
                                    
                                    5.9%
                                 | 
| 4 | 1-2 times per year | 104 | 
                                    
                                    2.8%
                                 | 
| 5 | Never | 380 | 
                                    
                                    10.3%
                                 | 
| Sysmiss | 3281 |