| Value | Category | Cases | |
|---|---|---|---|
| -9 | NIU (not in universe) | 426 |
65.1%
|
| 1 | ever used | 3 |
0.5%
|
| 2 | never used | 223 |
34.1%
|
| 3 | don't know about it | 2 |
0.3%
|
| 9999995 | missing:impute | 0 |
0%
|