Year Percent 1970 0.98631 1971 0.98436 1972 0.97685 1973 0.98173 1974 0.9915 1975 0.99298 1978 0.99862 1981 0.96042 1982 0.96858 1984 1.01721 1985 1.03713 1986 1.00784 1990 0.98822 1991 1.0085 1993 0.99511 1998 1.04589 1999 1.03588 2000 1.02132 2001 1.01974 2002 1.02004 2006 0.98107 2007 0.84403 2008 0.99111 2009 1.11361 2010 1.02034 2011 0.97714 2012 1.01539 2013 1.01673 2014 1.03597