Value | Category | Cases | |
---|---|---|---|
-8 | Don’t Know | 7 |
3.5%
|
1937 | 1 |
0.5%
|
|
1953 | 1 |
0.5%
|
|
1954 | 1 |
0.5%
|
|
1955 | 1 |
0.5%
|
|
1957 | 1 |
0.5%
|
|
1960 | 4 |
2%
|
|
1962 | 1 |
0.5%
|
|
1963 | 2 |
1%
|
|
1965 | 3 |
1.5%
|
|
1968 | 4 |
2%
|
|
1969 | 2 |
1%
|
|
1970 | 2 |
1%
|
|
1972 | 2 |
1%
|
|
1974 | 2 |
1%
|
|
1975 | 11 |
5.5%
|
|
1976 | 2 |
1%
|
|
1977 | 2 |
1%
|
|
1978 | 2 |
1%
|
|
1979 | 3 |
1.5%
|
|
1980 | 3 |
1.5%
|
|
1981 | 1 |
0.5%
|
|
1982 | 7 |
3.5%
|
|
1983 | 3 |
1.5%
|
|
1984 | 2 |
1%
|
|
1985 | 2 |
1%
|
|
1986 | 1 |
0.5%
|
|
1987 | 1 |
0.5%
|
|
1988 | 1 |
0.5%
|
|
1989 | 2 |
1%
|
|
1990 | 4 |
2%
|
|
1991 | 8 |
4%
|
|
1992 | 5 |
2.5%
|
|
1993 | 5 |
2.5%
|
|
1994 | 4 |
2%
|
|
1995 | 3 |
1.5%
|
|
1996 | 5 |
2.5%
|
|
1997 | 10 |
5%
|
|
1998 | 2 |
1%
|
|
1999 | 4 |
2%
|
|
2000 | 4 |
2%
|
|
2001 | 4 |
2%
|
|
2002 | 7 |
3.5%
|
|
2003 | 5 |
2.5%
|
|
2004 | 4 |
2%
|
|
2005 | 7 |
3.5%
|
|
2006 | 10 |
5%
|
|
2007 | 4 |
2%
|
|
2008 | 4 |
2%
|
|
2009 | 5 |
2.5%
|
|
2010 | 4 |
2%
|
|
2011 | 3 |
1.5%
|
|
2012 | 2 |
1%
|
|
2013 | 4 |
2%
|
|
2014 | 2 |
1%
|
|
2015 | 2 |
1%
|
|
2016 | 2 |
1%
|