Year	Percent
1999-01-01	25.850
2000-01-01	27.125
2001-01-01	25.925
2002-01-01	27.700
2003-01-01	28.900
2004-01-01	31.175
2005-01-01	33.275
2006-01-01	33.600
2007-01-01	35.875
2008-01-01	36.100
2009-01-01	37.150
2010-01-01	39.125
2011-01-01	40.325
2012-01-01	41.325
2013-01-01	44.100
2014-01-01	45.075
2015-01-01	46.625
2016-01-01	48.175
2017-01-01	51.275