| Value | Category | Cases | |
|---|---|---|---|
| 1 | None | 4318 |
92.4%
|
| 2 | Once | 238 |
5.1%
|
| 3 | Twice | 56 |
1.2%
|
| 4 | Three times | 26 |
0.6%
|
| 5 | Four times or more | 35 |
0.7%
|
| Sysmiss | 1998 |