| Value | Category | Cases | |
|---|---|---|---|
| 1984 | 1 |
0.3%
|
|
| 1985 | 1 |
0.3%
|
|
| 1986 | 3 |
1%
|
|
| 1987 | 6 |
2%
|
|
| 1988 | 8 |
2.7%
|
|
| 1989 | 11 |
3.7%
|
|
| 1990 | 19 |
6.4%
|
|
| 1991 | 13 |
4.4%
|
|
| 1992 | 18 |
6.1%
|
|
| 1993 | 23 |
7.8%
|
|
| 1994 | 35 |
11.9%
|
|
| 1995 | 23 |
7.8%
|
|
| 1996 | 27 |
9.2%
|
|
| 1997 | 27 |
9.2%
|
|
| 1998 | 30 |
10.2%
|
|
| 1999 | 39 |
13.2%
|
|
| 2000 | 10 |
3.4%
|
|
| 9997 | inconsistent | 0 |
0%
|
| 9998 | dk | 1 |
0.3%
|
| Sysmiss | 15690 |