Year	Percent
1998-01-01	55.3150754099152
1999-01-01	55.4865839942593
2000-01-01	56.3728548043315
2001-01-01	56.7647153655464
2002-01-01	56.0488487071322
2003-01-01	54.8885184467792
2004-01-01	54.2332365628569
2005-01-01	53.5528781955126
2006-01-01	53.8404026600039
2007-01-01	53.7896279350512
2008-01-01	53.7844717340150
2009-01-01	51.5771983945812
2010-01-01	50.8160493180688
2011-01-01	49.3619949105317
2012-01-01	47.0601941805745
2013-01-01	46.0366053979328
2014-01-01	47.0958302911128