Year	Percent
1998-01-01	37.150
1999-01-01	37.550
2000-01-01	36.275
2001-01-01	37.075
2002-01-01	40.750
2003-01-01	42.250
2004-01-01	42.675
2005-01-01	44.475
2006-01-01	45.200
2007-01-01	46.000
2008-01-01	47.600
2009-01-01	46.850
2010-01-01	46.500
2011-01-01	47.675
2012-01-01	49.325
2013-01-01	51.625
2014-01-01	54.000
2015-01-01	55.450
2016-01-01	58.525
2017-01-01	62.125