Year Percent 2001-01-01 0.000000000000000000 2002-01-01 0.000000000000000000 2003-01-01 0.022000000000000002 2004-01-01 0.022000000000000002 2005-01-01 0.480000000000000000 2006-01-01 2.350000000000000000 2007-01-01 3.630000000000000000 2008-01-01 4.630000000000000000 2009-01-01 6.190000000000000000 2010-01-01 7.220000000000000000 2011-01-01 8.210000000000000000 2012-01-01 9.380000000000000000 2013-01-01 9.700000000000000000 2014-01-01 10.440000000000000000 2015-01-01 10.190000000000000000 2016-01-01 11.130000000000000000