Year Percent 1993 12.89751 1994 16.51075 1995 17.23298 1996 19.92203 1997 47.3282 1998 31.17908 1999 26.5902 2000 21.41422 2001 20.88781 2002 25.61687 2003 33.54092 2004 38.09993 2005 49.12479 2006 43.27184 2007 63.4004 2008 33.80482 2009 46.43472 2010 48.2858 2011 39.54118 2012 39.49878 2013 46.57603 2014 46.66011 2015 59.6809 2016 34.84543 2017 29.32007