Year	Percent
1999-01-01	51.1564341844543
2000-01-01	51.2109898537515
2001-01-01	51.4408037119824
2002-01-01	51.0110630087026
2003-01-01	50.5244092097938
2004-01-01	50.9042145492881
2005-01-01	51.0076338101010
2006-01-01	51.8097985105604
2007-01-01	51.5622523267065
2008-01-01	52.0106027462372
2009-01-01	50.2161649264278
2010-01-01	48.8279839805701
2011-01-01	48.5617414685038
2012-01-01	48.1323586411977
2013-01-01	47.9197514277398
2014-01-01	48.1408010669275