| Value | Category | Cases | |
|---|---|---|---|
| 0 | Less than one year | 0 |
0%
|
| 1 | 2 |
40%
|
|
| 8 | 1 |
20%
|
|
| 12 | 1 |
20%
|
|
| 20 | 1 |
20%
|
|
| Sysmiss | 2228 |