Year Percent 1995 2.09125 1996 2.13714 1997 5.21673 1998 3.749 1999 3.38029 2000 3.81839 2001 5.0208 2002 5.20392 2003 7.49202 2004 5.40176 2005 7.95652 2006 9.72289 2007 23.66737 2008 46.53005 2009 42.45723 2010 26.60022 2011 22.56797 2012 25.58624 2013 29.75495 2014 29.83102 2015 29.22104 2016 25.48755