Year Percent 1961 0.01662 1962 0.06202 1963 2.79136 1964 1.56135 1965 -5.51785 1966 -2.61188 1967 10.65947 1968 5.54133 1969 0.42917 1970 10.34897 1971 4.66274 1972 5.26494 1973 9.33814 1974 0.55398 1975 -1.42375 1976 0.82577 1977 4.00299 1978 0.01017 1979 10.02325 1980 -3.72812 1981 3.76548 1982 -8.40473 1983 -6.36928 1984 6.0754 1985 -6.12739 1986 6.71717 1987 -7.0261 1988 0.78929 1989 7.18554 1990 5.2186 1991 -3.60557 1992 4.80918 1993 0.71041 1994 3.63935 1995 1.2006 1996 3.60061 1997 -3.23417 1998 0.35638 1999 7.96642 2000 -2.27304 2001 1.62481 2002 3.01364 2003 0.88411 2004 5.07791 2005 0.27567 2006 1.16387 2007 -1.72966 2008 0.01113 2009 -2.3846 2010 1.99893 2011 1.85989 2012 0.6556 2013 4.00572 2014 4.87736 2015 3.10609 2016 -0.35836 2017 3.02715