Year Percent 1961 -5.75103 1962 2.93351 1963 2.0405 1964 3.98192 1965 -0.07118 1966 -0.99646 1967 0.02839 1968 1.22443 1969 3.35529 1970 -1.31807 1971 0.76587 1972 3.48998 1973 7.5528 1974 20.12852 1975 22.86596 1976 -1.89827 1977 11.03022 1978 1.67504 1979 9.91159 1980 9.47952 1981 1.20343 1982 4.60261 1983 -2.85185 1984 5.26715 1985 1.18542 1986 0.47289 1987 16.84706 1988 8.95795 1989 3.27009 1990 -0.16733 1991 5.54465 1992 -1.06322 1993 7.0761 1994 5.34436 1995 6.51069 1996 5.46555 1997 -10.00882 1998 -6.6667 1999 0.91775 2000 -6.89174 2001 -4.31703 2002 0.44321 2003 9.67241 2004 11.19655 2005 10.04984 2006 1.64774 2007 11.69924 2008 7.34935 2009 29.05327 2010 5.47371 2011 10.48845 2012 3.98777 2013 3.17744 2014 2.69634 2015 1.04322 2016 4.97358 2017 0.25221