| Value | Category | Cases | |
|---|---|---|---|
| 1994 | 1 |
25%
|
|
| 2000 | 1 |
25%
|
|
| 2011 | 1 |
25%
|
|
| 2015 | 1 |
25%
|
|
| 9998 | Don't know | 0 |
0%
|
| Sysmiss | 4540 |