Year	Percent
1999-01-01	34.825
2000-01-01	34.150
2001-01-01	34.575
2002-01-01	33.800
2003-01-01	33.025
2004-01-01	32.675
2005-01-01	31.900
2006-01-01	31.600
2007-01-01	31.475
2008-01-01	31.300
2009-01-01	32.175
2010-01-01	32.675
2011-01-01	33.175
2012-01-01	33.650
2013-01-01	34.375
2014-01-01	34.975
2015-01-01	35.175
2016-01-01	35.700
2017-01-01	36.100