| Value | Category | Cases | |
|---|---|---|---|
| 1978 | 1 |
0.3%
|
|
| 1979 | 1 |
0.3%
|
|
| 1980 | 3 |
1%
|
|
| 1981 | 1 |
0.3%
|
|
| 1982 | 2 |
0.6%
|
|
| 1983 | 1 |
0.3%
|
|
| 1984 | 5 |
1.6%
|
|
| 1985 | 1 |
0.3%
|
|
| 1986 | 7 |
2.3%
|
|
| 1987 | 5 |
1.6%
|
|
| 1988 | 7 |
2.3%
|
|
| 1989 | 8 |
2.6%
|
|
| 1990 | 10 |
3.2%
|
|
| 1991 | 8 |
2.6%
|
|
| 1992 | 12 |
3.9%
|
|
| 1993 | 9 |
2.9%
|
|
| 1994 | 11 |
3.5%
|
|
| 1995 | 14 |
4.5%
|
|
| 1996 | 9 |
2.9%
|
|
| 1997 | 11 |
3.5%
|
|
| 1998 | 9 |
2.9%
|
|
| 1999 | 11 |
3.5%
|
|
| 2000 | 14 |
4.5%
|
|
| 2001 | 14 |
4.5%
|
|
| 2002 | 11 |
3.5%
|
|
| 2003 | 7 |
2.3%
|
|
| 2004 | 8 |
2.6%
|
|
| 2005 | 16 |
5.1%
|
|
| 2006 | 15 |
4.8%
|
|
| 2007 | 14 |
4.5%
|
|
| 2008 | 11 |
3.5%
|
|
| 2009 | 21 |
6.8%
|
|
| 2010 | 17 |
5.5%
|
|
| 2011 | 8 |
2.6%
|
|
| 2012 | 1 |
0.3%
|
|
| 9997 | Inconsistent | 0 |
0%
|
| 9998 | DK | 7 |
2.3%
|
| 9999 | Missing | 1 |
0.3%
|
| Sysmiss | 207 |