Year	Percent
1997-01-01	11.420500000000000
1998-01-01	13.463800000000000
1999-01-01	11.992600000000000
2000-01-01	6.386340000000001
2001-01-01	8.223460000000001
2002-01-01	25.993600000000000
2003-01-01	28.595500000000000
2004-01-01	25.589000000000002
2005-01-01	18.657300000000000
2006-01-01	7.085310000000001
2007-01-01	19.752600000000000
2008-01-01	22.261800000000000
2009-01-01	19.684700000000000
2010-01-01	22.384500000000000
2011-01-01	19.805200000000000
2012-01-01	20.976000000000000
2013-01-01	16.698700000000000
2014-01-01	20.794100000000000
2015-01-01	19.781400000000000
2016-01-01	22.069500000000000