| Value | Category | Cases | |
|---|---|---|---|
| 1994 | 7 |
0.4%
|
|
| 1995 | 33 |
2%
|
|
| 1996 | 189 |
11.3%
|
|
| 1997 | 331 |
19.9%
|
|
| 1998 | 420 |
25.2%
|
|
| 1999 | 510 |
30.6%
|
|
| 2000 | 177 |
10.6%
|
|
| 9997 | inconsistent | 0 |
0%
|
| 9998 | dk | 0 |
0%
|
| Sysmiss | 14318 |