Year Percent 1992 84.40643 1993 71.63175 1994 66.23716 1995 67.42304 1996 71.72404 1997 77.22301 1998 79.7951 1999 70.78652 2000 84.46438 2001 89.09528 2002 88.27262 2003 94.92433 2004 100.63902 2005 106.12637 2006 123.01852 2007 138.03726 2008 144.58434 2009 125.61762 2010 144.90296 2011 162.63056 2012 169.15008 2013 170.07221 2014 166.83146 2015 169.9247 2016 170.51434 2017 175.22995