| Value | Category | Cases | |
|---|---|---|---|
| 1 | Light | 2131 |
30.2%
|
| 2 | Medium | 389 |
5.5%
|
| 3 | Heavy | 271 |
3.8%
|
| 4 | Cannot recall | 37 |
0.5%
|
| 5 | None | 4220 |
59.9%
|
| Sysmiss | 438 |