Year	Percent
1998-01-01	46.430
1999-01-01	48.590
2000-01-01	51.500
2001-01-01	47.300
2002-01-01	42.080
2003-01-01	43.100
2004-01-01	48.940
2005-01-01	47.830
2006-01-01	47.450
2007-01-01	52.440
2008-01-01	43.435
2009-01-01	43.290
2010-01-01	47.755
2011-01-01	47.990
2012-01-01	45.090
2013-01-01	54.040
2014-01-01	51.870
2015-01-01	48.140