| Value | Category | Cases | |
|---|---|---|---|
| 1975 | 1 |
0.1%
|
|
| 1976 | 1 |
0.1%
|
|
| 1977 | 1 |
0.1%
|
|
| 1978 | 3 |
0.3%
|
|
| 1979 | 9 |
1%
|
|
| 1980 | 12 |
1.3%
|
|
| 1981 | 8 |
0.9%
|
|
| 1982 | 11 |
1.2%
|
|
| 1983 | 14 |
1.6%
|
|
| 1984 | 17 |
1.9%
|
|
| 1985 | 10 |
1.1%
|
|
| 1986 | 24 |
2.7%
|
|
| 1987 | 26 |
2.9%
|
|
| 1988 | 21 |
2.3%
|
|
| 1989 | 21 |
2.3%
|
|
| 1990 | 39 |
4.3%
|
|
| 1991 | 26 |
2.9%
|
|
| 1992 | 27 |
3%
|
|
| 1993 | 24 |
2.7%
|
|
| 1994 | 23 |
2.6%
|
|
| 1995 | 25 |
2.8%
|
|
| 1996 | 20 |
2.2%
|
|
| 1997 | 28 |
3.1%
|
|
| 1998 | 24 |
2.7%
|
|
| 1999 | 37 |
4.1%
|
|
| 2000 | 49 |
5.5%
|
|
| 2001 | 25 |
2.8%
|
|
| 2002 | 35 |
3.9%
|
|
| 2003 | 30 |
3.3%
|
|
| 2004 | 30 |
3.3%
|
|
| 2005 | 38 |
4.2%
|
|
| 2006 | 29 |
3.2%
|
|
| 2007 | 32 |
3.6%
|
|
| 2008 | 43 |
4.8%
|
|
| 2009 | 29 |
3.2%
|
|
| 2010 | 46 |
5.1%
|
|
| 2011 | 26 |
2.9%
|
|
| 9997 | Inconsistent | 0 |
0%
|
| 9998 | DK | 32 |
3.6%
|
| 9999 | Missing | 3 |
0.3%
|
| Sysmiss | 315 |