Year Percent 1996 85.22601 1997 18.4059 1998 25.41363 1999 33.23648 2000 78.57853 2001 89.24465 2002 18.04328 2003 12.58947 2004 9.08699 2005 14.32937 2006 11.86185 2007 8.21799 2008 10.61711 2009 8.29804 2010 5.87933 2011 9.56104 2012 6.26358 2013 5.43983 2014 2.70811 2015 2.676 2016 2.53455 2017 2.83572