| Value | Category | Cases | |
|---|---|---|---|
| 0 | Not at all | 1 |
0.6%
|
| 1 | Once a term | 65 |
41.7%
|
| 2 | Twice every term | 55 |
35.3%
|
| 3 | More than twice a term | 35 |
22.4%
|
| Sysmiss | 151 |