| Value | Category | Cases | |
|---|---|---|---|
| -9 | NIU (not in universe) | 4 |
0.1%
|
| 1 | easy to use method | 2555 |
90.5%
|
| 2 | hard to use method | 257 |
9.1%
|
| 98 | don't know | 6 |
0.2%
|
| 9999995 | missing:impute | 0 |
0%
|