Year	Percent
1999-01-01	24.575
2000-01-01	26.300
2001-01-01	25.100
2002-01-01	26.575
2003-01-01	28.125
2004-01-01	30.000
2005-01-01	31.800
2006-01-01	31.975
2007-01-01	34.375
2008-01-01	34.500
2009-01-01	35.225
2010-01-01	37.350
2011-01-01	38.700
2012-01-01	39.500
2013-01-01	41.725
2014-01-01	42.675
2015-01-01	44.025
2016-01-01	45.425
2017-01-01	48.225