Year Percent 1960 4.29754 1961 4.20731 1962 4.14856 1963 4.16104 1964 4.30996 1965 4.47401 1966 4.74105 1967 4.88899 1968 4.68926 1969 4.02665 1970 3.11901 1971 2.13582 1972 1.34616 1973 1.02138 1974 0.87435 1975 1.51808 1976 2.39634 1977 3.08514 1978 3.59866 1979 3.808 1980 3.80832 1981 3.2631 1982 3.13081 1983 3.04519 1984 2.86816 1985 2.64101 1986 2.35097 1987 2.07518 1988 1.94091 1989 1.97378 1990 2.09653 1991 2.27382 1992 2.35387 1993 2.19839 1994 1.76442 1995 -0.51791 1996 -1.67179 1997 -2.26957 1998 -2.6783 1999 -2.84574 2000 -2.21375 2001 -0.25042 2002 -0.17148 2003 -0.155 2004 -0.22245 2005 -0.3578 2006 -0.51155 2007 -0.60796 2008 -0.5988 2009 -0.52475 2010 -0.36291 2011 -0.10826 2012 0.11692 2013 0.33269 2014 0.49483 2015 0.65456 2016 0.79424 2017 0.93897