Year Percent 1999-01-01 0.006548000000000000 2000-01-01 0.003414000000000000 2001-01-01 0.007183000000000000 2002-01-01 0.012027000000000000 2003-01-01 0.019103000000000000 2004-01-01 0.020852000000000002 2005-01-01 0.005058000000000000 2006-01-01 0.002097000000000000 2007-01-01 0.007837000000000000 2008-01-01 0.002497000000000000 2009-01-01 0.002529000000000000 2010-01-01 0.003440000000000000 2011-01-01 0.007020000000000000 2012-01-01 0.027554000000000002 2013-01-01 0.075431000000000000 2014-01-01 0.129973000000000000 2015-01-01 0.157917000000000000