Year Percent 1960 1.93631 1961 2.17376 1962 2.29818 1963 2.13617 1964 1.61215 1965 0.87284 1966 0.01748 1967 -0.69061 1968 -1.02185 1969 -0.80344 1970 -0.18192 1971 0.59191 1972 1.22173 1973 1.60364 1974 1.62417 1975 1.39768 1976 1.10551 1977 0.90332 1978 0.80187 1979 0.85443 1980 1.00396 1981 1.18694 1982 1.29558 1983 1.27043 1984 1.06711 1985 0.74842 1986 0.38133 1987 0.07123 1988 -0.12027 1989 -0.13872 1990 -0.03281 1991 0.12081 1992 0.23214 1993 0.27144 1994 0.19958 1995 0.05282 1996 -0.11597 1997 -0.24301 1998 -0.3053 1999 -0.41933 2000 -0.02797 2001 0.40236 2002 0.40075 2003 0.39915 2004 0.17722 2005 0.14793 2006 0.1243 2007 0.13811 2008 0.17748 2009 0.21453 2010 0.18324 2011 0.10504 2012 0.08415 2013 0.0976 2014 0.09702 2015 0.05611 2016 0.02314 2017 0.02699