Year	Percent
1998-01-01	44.230
1999-01-01	45.350
2000-01-01	45.300
2001-01-01	43.900
2002-01-01	48.160
2003-01-01	47.670
2004-01-01	47.840
2005-01-01	47.570
2006-01-01	47.160
2007-01-01	49.520
2008-01-01	44.425
2009-01-01	45.240
2010-01-01	49.230
2011-01-01	46.870
2012-01-01	51.970
2013-01-01	49.920
2014-01-01	51.080
2015-01-01	54.110