| Value | Category | Cases | |
|---|---|---|---|
| 0 | Zero | 37 |
58.7%
|
| 1 | Once | 21 |
33.3%
|
| 2 | Twice | 1 |
1.6%
|
| 3 | More than twice or blank | 4 |
6.3%
|
| 9 | Missing | 0 | |
| Sysmiss | 20 |