Year Percent 1990 5.02774 1991 4.70043 1992 3.78258 1993 2.74159 1994 3.56264 1995 4.59733 1996 4.28049 1997 4.33087 1998 4.35285 1999 4.16113 2000 3.87325 2001 5.70227 2002 3.59707 2003 3.17379 2004 3.22667 2005 3.2505 2006 0.71377 2007 0.7137 2008 0.72447 2009 0.91253 2010 0.93816 2011 0.9104 2012 0.90556 2013 0.89142 2014 0.88758 2015 0.89773 2016 0.98619 2017 0.98254 2018 0.98149 2019 0.97796 2020 0.99418