| Value | Category | Cases | |
|---|---|---|---|
| 1 | Once | 118 |
0.7%
|
| 2 | Twice | 122 |
0.8%
|
| 3 | Three times | 61 |
0.4%
|
| 4 | Four times | 20 |
0.1%
|
| 5 | More | 16 |
0.1%
|
| 6 | Never | 15516 |
97.9%
|
| Sysmiss | 1528 |