Year Percent 1960 -3.64792 1961 -4.64574 1962 -5.59857 1963 -6.26372 1964 -7.60183 1965 -4.31278 1966 -4.0506 1967 -3.80224 1968 -3.74402 1969 -4.49209 1970 -5.78989 1971 -5.14524 1972 -4.81896 1973 -7.77148 1974 -8.41266 1975 -11.44794 1976 -10.3003 1977 -13.01857 1978 -11.54483 1979 -16.85903 1980 -11.92077 1981 -7.56086 1982 -6.93285 1983 -7.12265 1984 -6.03522 1985 -19.4204 1986 -21.98169 1987 -20.98323 1988 -15.0851 1989 -17.62724 1990 -14.42661 1991 -12.44628 1992 -13.72307 1993 -16.00044 1994 -18.77715 1995 -11.83852 1996 -11.52301 1997 -12.22543 1998 -11.07573 1999 -13.87163 2000 -17.79098 2001 -34.99033 2002 -100.97093 2003 -34.11298 2004 0.24913 2005 10.1078 2006 -0.74435 2007 4.27596 2008 5.09934 2009 -6.83276 2010 -6.6995 2011 -2.92656 2012 -3.63951 2013 -5.51773 2014 -8.3038 2015 -6.53687 2016 -11.47914 2017 -5.82581