| Value | Category | Cases | |
|---|---|---|---|
| 2001 | 1 |
5%
|
|
| 2002 | 1 |
5%
|
|
| 2003 | 4 |
20%
|
|
| 2004 | 4 |
20%
|
|
| 2005 | 1 |
5%
|
|
| 9997 | Inconsistent | 0 |
0%
|
| 9998 | DK | 9 |
45%
|
| 9999 | Missing | 0 |
0%
|
| Sysmiss | 364 |