| Value | Category | Cases | |
|---|---|---|---|
| 1974 | 1 |
0.1%
|
|
| 1977 | 2 |
0.3%
|
|
| 1978 | 2 |
0.3%
|
|
| 1979 | 8 |
1.2%
|
|
| 1980 | 2 |
0.3%
|
|
| 1981 | 5 |
0.7%
|
|
| 1982 | 11 |
1.6%
|
|
| 1983 | 10 |
1.5%
|
|
| 1984 | 7 |
1%
|
|
| 1985 | 11 |
1.6%
|
|
| 1986 | 12 |
1.8%
|
|
| 1987 | 16 |
2.4%
|
|
| 1988 | 22 |
3.3%
|
|
| 1989 | 14 |
2.1%
|
|
| 1990 | 15 |
2.2%
|
|
| 1991 | 17 |
2.5%
|
|
| 1992 | 25 |
3.7%
|
|
| 1993 | 23 |
3.4%
|
|
| 1994 | 31 |
4.6%
|
|
| 1995 | 20 |
3%
|
|
| 1996 | 26 |
3.9%
|
|
| 1997 | 24 |
3.6%
|
|
| 1998 | 24 |
3.6%
|
|
| 1999 | 29 |
4.3%
|
|
| 2000 | 33 |
4.9%
|
|
| 2001 | 29 |
4.3%
|
|
| 2002 | 35 |
5.2%
|
|
| 2003 | 31 |
4.6%
|
|
| 2004 | 31 |
4.6%
|
|
| 2005 | 45 |
6.7%
|
|
| 2006 | 61 |
9.1%
|
|
| 2007 | 47 |
7%
|
|
| 9997 | Inconsistent | 2 |
0.3%
|
| 9998 | DK | 0 |
0%
|
| Sysmiss | 9699 |