| Value | Category | Cases | |
|---|---|---|---|
| -9 | Don't know | 0 |
0%
|
| 1992 | 1 |
25%
|
|
| 2000 | 1 |
25%
|
|
| 2007 | 1 |
25%
|
|
| 2010 | 1 |
25%
|