Year	Percent
2001-01-01	14.08
2002-01-01	16.35
2003-01-01	17.58
2004-01-01	22.62
2005-01-01	24.51
2006-01-01	27.47
2007-01-01	30.51
2008-01-01	27.48
2009-01-01	31.18
2010-01-01	34.25
2011-01-01	31.97
2012-01-01	34.43
2013-01-01	37.36
2014-01-01	37.31
2015-01-01	37.24
2016-01-01	37.75