| Value | Category | Cases | |
|---|---|---|---|
| 0 | never happened | 7142 |
94%
|
| 1 | rarely(1-2 times) | 281 |
3.7%
|
| 2 | sometimes(3-10 times) | 118 |
1.6%
|
| 3 | often(more than 10 times) | 58 |
0.8%
|
| Sysmiss | 95 |