| Value | Category | Cases | |
|---|---|---|---|
| -9 | NIU (not in universe) | 2612 |
92.6%
|
| 1 | easy to use method | 77 |
2.7%
|
| 2 | hard to use method | 100 |
3.5%
|
| 98 | don't know | 2 |
0.1%
|
| 9999995 | missing:impute | 31 |
1.1%
|