Year Percent 1961 5.18486 1962 3.68533 1963 4.7359 1964 6.02635 1965 2.84821 1966 1.12398 1967 2.57548 1968 3.05744 1969 4.27429 1970 5.05673 1971 0.25243 1972 1.98692 1973 3.78893 1974 2.89918 1975 2.14625 1976 0.69124 1977 -1.94513 1978 1.45573 1979 3.61365 1980 1.49373 1981 0.33444 1982 1.19078 1983 1.85452 1984 4.13487 1985 1.99177 1986 2.45277 1987 3.00955 1988 2.08876 1989 1.97219 1990 -0.02076 1991 -1.81752 1992 -1.73663 1993 -2.63281 1994 3.35047 1995 3.47992 1996 1.35643 1997 2.84158 1998 4.16895 1999 4.44873 2000 4.56724 2001 1.29111 2002 1.74193 2003 2.00548 2004 3.91104 2005 2.40794 2006 4.10093 2007 2.64098 2008 -1.32873 2009 -5.98896 2010 5.08919 2011 1.89206 2012 -1.02124 2013 0.38696 2014 1.5913 2015 3.42252 2016 1.94596 2017 0.81838