Year Percent 1961 5.90875 1962 -2.64349 1963 10.02554 1964 13.05833 1965 -6.78247 1966 7.46425 1967 0.79847 1968 8.4059 1969 5.31945 1970 5.86048 1971 4.7234 1972 -0.44976 1973 1.06699 1974 -0.49454 1975 3.28429 1976 7.78886 1977 2.49051 1978 5.98111 1979 -2.10135 1980 -14.81623 1981 -0.92407 1982 -4.01368 1983 -7.85578 1984 -6.596 1985 0.44793 1986 -0.60752 1987 -3.96061 1988 -2.44543 1989 -0.66048 1990 -4.55062 1991 -3.44007 1992 -3.67769 1993 -3.56058 1994 -2.4878 1995 3.75738 1996 4.4646 1997 0.71616 1998 2.03359 1999 -0.97388 2000 -4.33572 2001 -1.95619 2002 -3.51558 2003 -3.10499 2004 -0.55903 2005 -0.15695 2006 -0.45554 2007 -0.29579 2008 0.37583 2009 0.98106 2010 -0.30744 2011 -6.64761 2012 8.00176 2013 6.17437 2014 6.06575 2015 6.12457 2016 5.6562 2017 5.13996