Year Percent 1990 3.02 1991 3.3 1992 2.81 1993 2.55 1994 2.82 1995 3.04 1996 4.6 1997 3.79 1998 3.48 1999 3.81 2000 3.25 2001 3.73 2002 4.13 2003 4.14 2004 4.18 2005 4.33 2006 3.53 2007 2.79 2008 3.27 2009 5.54 2010 4.93 2011 7.89 2012 7.31 2013 6.35 2014 6.2 2015 6.76 2016 6.46 2017 6.31 2018 7.48 2019 8.77 2020 14.83