Year	Percent
1999-01-01	40.5125
2000-01-01	37.9017
2001-01-01	43.7863
2002-01-01	35.9580
2003-01-01	43.0554
2004-01-01	46.9585
2005-01-01	51.9779
2006-01-01	61.8145
2007-01-01	63.8363
2008-01-01	35.9229
2009-01-01	65.0828
2010-01-01	68.3655
2011-01-01	52.5247
2012-01-01	63.0946
2013-01-01	71.9666
2014-01-01	70.0416
2015-01-01	79.9155
2016-01-01	77.1002