Year Percent 1971 0.98398 1972 0.98195 1973 0.99652 1974 0.99071 1975 0.99508 1976 0.99613 1977 1.00327 1978 1.00642 1979 1.00971 1980 1.01231 1981 1.01567 1982 1.01364 1983 1.02303 1984 1.01727 1985 1.01886 1986 1.01291 1987 1.01402 1988 1.01364 1989 1.01452 1990 1.01689 1991 1.0193 1992 1.0171 1993 1.03747 1994 1.03794 1995 1.04532 1996 1.04336 1999 1.04176 2000 1.05728 2001 1.06342 2002 1.06831 2003 1.05752 2004 1.05655 2005 1.06992 2006 1.07475 2007 1.07981 2008 1.08786 2009 1.08961 2010 1.08339 2011 1.0819 2012 1.08251 2013 1.08219 2014 1.07985 2015 1.08055