Year Percent 1966 1.51638 1967 -0.26647 1968 -0.27051 1969 1.22682 1970 0.57155 1971 25.04618 1972 1.4824 1973 15.10719 1974 162.80877 1975 -0.5974 1976 0.93185 1977 5.62003 1978 -1.95769 1979 40.805 1980 42.56671 1981 11.45341 1982 1.41685 1983 -11.31055 1984 0.34931 1985 4.85952 1986 -25.69954 1987 10.78617 1988 2.96596 1989 -1.72368 1993 -7.38642 1994 -5.87048 1995 4.8518 1996 15.51126 1997 -4.71944 1998 -17.14803 1999 18.07267 2000 20.52647 2001 -8.18019 2002 5.15304 2003 4.92456 2004 10.84995 2005 22.35761 2006 16.1734 2007 4.30679 2008 18.66198 2009 -17.21635 2010 11.16571 2011 17.22778 2012 7.4867 2013 0.22333 2014 -6.75791 2015 -25.95842 2016 -6.13364 2017 11.94655