Year	Percent
1998-01-01	64.31638336
1999-01-01	65.66393280
2000-01-01	64.93716431
2001-01-01	61.63194275
2002-01-01	63.80522919
2003-01-01	72.56324005
2004-01-01	62.25698853
2005-01-01	70.29100800
2006-01-01	83.03571320
2007-01-01	72.11821747
2008-01-01	62.53406525
2009-01-01	58.61221313
2010-01-01	57.14380646
2011-01-01	70.62466431
2012-01-01	77.51863861
2013-01-01	70.94738007