Year Percent 1961 5.61261 1962 2.4881 1963 -6.54831 1964 1.05321 1965 0.88355 1966 -1.39482 1967 -0.68297 1968 4.6375 1969 4.4944 1970 3.26742 1971 4.54866 1972 5.33211 1973 4.9374 1974 4.62362 1975 4.52351 1976 -2.03504 1977 -11.57617 1978 3.3226 1979 6.6776 1980 14.26044 1981 14.22145 1982 20.01753 1983 2.79978 1984 3.92601 1985 -3.95527 1986 -9.42729 1987 -2.53235 1988 -0.97243 1989 -0.15022 1990 -1.70865 1991 -0.35319 1992 -0.14595 1993 -3.65182 1994 -8.06151 1995 1.13396 1996 1.39394 1997 -3.41734 1998 0.81159 1999 -5.31218 2000 4.59511 2001 0.98264 2002 1.77719 2003 -1.93089 2004 0.52281 2005 4.48667 2006 2.8042 2007 -4.89597 2008 2.00165 2009 3.97541 2010 5.45484 2011 0.53221 2012 1.09746 2013 0.87112 2014 4.15578 2015 0.0874 2016 -5.26846 2017 -7.03621