Year Percent 2004-01-01 0.5968690000000000 2005-01-01 0.8207459999999999 2006-01-01 0.9232490000000000 2007-01-01 1.6840800000000000 2008-01-01 2.0946100000000000 2009-01-01 2.0249099999999998 2010-01-01 6.0912600000000000 2011-01-01 9.4440200000000000 2012-01-01 10.4313000000000000 2013-01-01 10.9049000000000000 2014-01-01 12.0717000000000000 2015-01-01 13.6801000000000000 2016-01-01 15.2213000000000000