Year % 1983 65.82307 1984 66.15596 1985 64.17211 1986 67.19113 1987 63.05025 1988 71.02542 1989 66.6985 1990 74.77594 1991 67.32437 1992 71.9708 1993 69.94721 1994 74.01227 1995 77.60988 1996 77.56301 1997 78.97355 1998 81.34819 1999 77.99549 2000 80.76002 2001 80.91838 2002 81.65054 2003 80.68959 2004 82.09752 2005 83.47745 2006 86.32062 2007 85.49036 2008 84.74182 2009 85.45101 2010 85.83628 2011 87.68455 2012 78.11437 2013 90.2434 2014 85.84674 2015 85.85682 2016 87.53936 2017 99.41551