Year	Percent
1997-01-01	61.0034
1998-01-01	55.7100
1999-01-01	43.4000
2000-01-01	36.7300
2001-01-01	41.4200
2002-01-01	47.4082
2003-01-01	41.6066
2004-01-01	36.0861
2005-01-01	36.6530
2006-01-01	35.8476
2007-01-01	30.3852
2008-01-01	41.3089
2009-01-01	32.0922
2010-01-01	29.8058
2011-01-01	30.7831
2012-01-01	25.7089
2013-01-01	20.2479
2014-01-01	22.2192
2015-01-01	34.6999
2016-01-01	39.3717