| Value | Category | Cases | |
|---|---|---|---|
| 1995 | 13 |
1.2%
|
|
| 1996 | 125 |
11.1%
|
|
| 1997 | 132 |
11.8%
|
|
| 1998 | 234 |
20.8%
|
|
| 1999 | 309 |
27.5%
|
|
| 2000 | 310 |
27.6%
|
|
| 9997 | inconsistent | 0 |
0%
|
| 9998 | dk | 0 |
0%
|
| Sysmiss | 5269 |