Year Percent 1961 -0.37766 1962 -0.19251 1963 -3.34582 1964 1.39643 1965 -2.9379 1966 -0.51141 1967 2.83661 1968 4.07106 1969 1.00817 1970 2.48484 1971 1.13737 1972 -3.95548 1973 -5.29081 1974 -0.8142 1975 -1.55883 1976 -5.78002 1977 -0.512 1978 -5.40629 1979 6.74885 1980 -2.04937 1981 -12.2634 1982 -4.60447 1983 -1.96596 1984 -1.1714 1985 -1.68498 1986 -0.88359 1987 -1.63112 1988 0.52725 1989 1.15784 1990 0.19603 1991 -9.00965 1992 -1.76287 1993 -0.91688 1994 -3.06248 1995 -1.37384 1996 -0.99055 1997 0.47623 1998 0.69735 1999 1.41488 2000 1.54231 2001 2.79623 2002 -15.29999 2003 6.51899 2004 2.1598 2005 1.55822 2006 1.99911 2007 3.216 2008 4.1126 2009 -6.68615 2010 -2.49815 2011 -1.30924 2012 0.24915 2013 -0.48174 2014 0.56254 2015 0.37516 2016 1.41605 2017 1.4155