Year Percent 1961 1.28233 1962 0.56542 1963 6.41224 1964 1.64632 1965 1.37912 1966 2.49318 1967 1.13734 1968 5.67388 1969 1.78774 1970 2.76931 1971 2.68523 1972 4.42305 1973 3.93222 1974 3.58908 1975 -0.66496 1976 4.69436 1977 5.15918 1978 2.44684 1979 2.17541 1980 1.23397 1981 -1.82034 1982 -5.90353 1983 -4.96392 1984 -1.94515 1985 -2.9875 1986 -2.21312 1987 1.14084 1988 1.50183 1989 1.55502 1990 0.72808 1991 1.25944 1992 2.4057 1993 1.52052 1994 1.64463 1995 2.56703 1996 0.65443 1997 2.05435 1998 2.6749 1999 1.53339 2000 1.26523 2001 -0.02047 2002 1.45133 2003 0.1388 2004 0.76251 2005 0.90173 2006 3.01229 2007 3.95084 2008 1.02416 2009 -1.64998 2010 0.66063 2011 1.94267 2012 0.79791 2013 1.53524 2014 2.03286 2015 2.03276 2016 1.04064 2017 0.74909