| Value | Category | Cases | |
|---|---|---|---|
| 1995 | 6 |
0.3%
|
|
| 1996 | 259 |
12.2%
|
|
| 1997 | 303 |
14.3%
|
|
| 1998 | 396 |
18.7%
|
|
| 1999 | 580 |
27.3%
|
|
| 2000 | 577 |
27.2%
|
|
| 9997 | inconsistent | 1 |
0%
|
| 9998 | dk | 0 |
0%
|
| Sysmiss | 1867 |