Year Percent 1961 -6.29929 1962 9.34449 1963 -11.34238 1964 -14.09159 1965 4.65249 1966 4.23145 1967 3.81221 1968 3.70846 1969 7.55182 1970 2.78429 1971 -1.77058 1972 -2.64043 1973 0.44712 1974 -1.57667 1975 -5.08455 1976 15.77518 1977 -1.25615 1978 5.60369 1979 8.16914 1980 5.29266 1981 1.97823 1982 -1.42172 1983 2.53787 1984 -7.63183 1985 0.33928 1986 0.73873 1987 -4.84244 1988 0.06854 1989 -2.6111 1990 -2.66596 1991 0.02983 1992 11.40041 1993 -2.24591 1994 -47.80555 1995 36.9809 1996 9.29631 1997 6.74173 1998 0.57176 1999 -3.00628 2000 2.53136 2001 4.52907 2002 10.44986 2003 0.50526 2004 5.7651 2005 7.26988 2006 6.67815 2007 4.88963 2008 8.17539 2009 3.38077 2010 4.51274 2011 5.25169 2012 5.89876 2013 2.04553 2014 4.96648 2015 6.20753 2016 3.42056 2017 3.57245