Year	Percent
1999-01-01	21.175
2000-01-01	22.675
2001-01-01	23.675
2002-01-01	24.850
2003-01-01	26.175
2004-01-01	27.550
2005-01-01	29.900
2006-01-01	31.150
2007-01-01	32.750
2008-01-01	34.250
2009-01-01	37.050
2010-01-01	38.450
2011-01-01	41.775
2012-01-01	43.875
2013-01-01	45.200
2014-01-01	46.900
2015-01-01	49.400
2016-01-01	51.700
2017-01-01	51.800