Year Percent 1990 0.85001 1991 0.82906 1992 0.84103 1993 0.81709 1994 0.79652 1995 1.39069 1996 1.35293 1997 1.31432 1998 1.27942 1999 1.24667 2000 1.21672 2001 1.21654 2002 1.18579 2003 1.18158 2004 1.13888 2005 1.14931 2006 1.80867 2007 1.77583 2008 1.06449 2009 1.07044 2010 1.02745 2011 0.98366 2012 1.46058 2013 1.43998 2014 1.6427 2015 1.55153 2016 1.51629 2017 1.49405 2018 1.44069 2019 1.39451 2020 1.47776