Year	Percent
1998-01-01	49.8358234016360
1999-01-01	49.1548391674513
2000-01-01	43.9479982121014
2001-01-01	42.4638720716351
2002-01-01	43.0180557647189
2003-01-01	42.7067872919363
2004-01-01	42.5543225230166
2005-01-01	43.2433299565134
2006-01-01	43.8196783385960
2007-01-01	44.5708355017534
2008-01-01	44.9148504026550
2009-01-01	44.2214395022241
2010-01-01	43.5221080771269
2011-01-01	43.6257935540129
2012-01-01	43.8100412555906
2013-01-01	43.2469796714615