Year Percent 1990 0 2001 0.1 2002 0.5 2003 0.6 2004 0.9 2005 0.9 2006 0.95234 2007 0.93 2008 1 2009 1.06 2010 2.5 2011 5 2012 7.1 2013 9.2 2014 13.21 2015 17.22 2016 21.23 2017 49.36