Year Percent 1990 4.16926 1991 4.01866 1992 2.83278 1993 2.73694 1994 3.31252 1995 3.56077 1996 3.67292 1997 3.54352 1998 3.34251 1999 3.13861 2000 3.08253 2001 2.90284 2002 2.76528 2003 2.61131 2004 2.43859 2005 2.1858 2006 1.72552 2007 1.35528 2008 1.12901 2009 0.98319 2010 0.92235 2011 0.88094 2012 0.83947 2013 0.78733 2014 0.71704 2015 0.64949 2016 1.09668 2017 1.07538 2018 1.03272 2019 1.0497 2020 1.07462