| Value | Category | Cases | |
|---|---|---|---|
| 1 | 1. every week | 97 |
2.9%
|
| 2 | 2. every month | 258 |
7.8%
|
| 3 | 3. every term | 1503 |
45.4%
|
| 4 | 4. every semester | 408 |
12.3%
|
| 5 | 5. once | 754 |
22.8%
|
| 6 | 6. never | 292 |
8.8%
|
| Sysmiss | 1226 |