Year	Percent
1999-01-01	33.500
2000-01-01	35.975
2001-01-01	37.475
2002-01-01	39.400
2003-01-01	41.100
2004-01-01	42.925
2005-01-01	45.600
2006-01-01	47.525
2007-01-01	49.100
2008-01-01	49.325
2009-01-01	47.450
2010-01-01	47.000
2011-01-01	46.750
2012-01-01	45.425
2013-01-01	44.500
2014-01-01	44.950
2015-01-01	46.150
2016-01-01	47.425
2017-01-01	48.400