Year	Percent
2001-01-01	49.39
2002-01-01	49.13
2003-01-01	48.96
2004-01-01	47.22
2005-01-01	46.99
2006-01-01	47.09
2007-01-01	46.32
2008-01-01	43.52
2009-01-01	50.87
2010-01-01	54.17
2011-01-01	52.27
2012-01-01	54.80
2013-01-01	58.26
2014-01-01	57.86
2015-01-01	59.45
2016-01-01	59.92