Year Percent 1990 0 1996 0 1997 0.43979 1998 0.86273 1999 2.51567 2000 3.52042 2001 5.89384 2002 6.8734 2003 7.25574 2004 6.75885 2005 6.68358 2006 8.29972 2007 16.68 2008 20 2009 26.8 2010 35.8278 2011 48 2012 60 2013 66.45 2014 70.22 2015 73.53 2016 76.85