Year Percent 1992 0.53217 1993 0.53989 1994 0.54831 1995 0.49569 1996 0.55987 1997 0.57677 1998 0.87475 1999 0.93145 2000 0.98017 2001 1.03726 2002 1.66322 2003 1.61616 2004 1.75375 2005 1.86244 2006 1.5853 2007 1.58623 2008 1.58736 2009 1.66121 2010 1.68484 2011 1.57586 2012 1.58603 2013 1.49797 2014 1.85525 2015 1.92917 2016 2.00752 2017 2.32751 2018 2.6947 2019 2.50833 2020 2.48962