| Value | Category | Cases | |
|---|---|---|---|
| 1 | Never | 1957 |
98.4%
|
| 2 | Once | 17 |
0.9%
|
| 3 | Twice | 4 |
0.2%
|
| 4 | 3-5 times | 4 |
0.2%
|
| 5 | 6-10 times | 1 |
0.1%
|
| 6 | 11-20 times | 0 |
0%
|
| 7 | More than 20 times | 2 |
0.1%
|
| Sysmiss | 3 |