Year	Percent
1999-01-01	18.8214
2000-01-01	14.4073
2001-01-01	16.3759
2002-01-01	16.6041
2003-01-01	15.8713
2004-01-01	19.9077
2005-01-01	18.7457
2006-01-01	27.3585
2007-01-01	28.9198
2008-01-01	35.4105
2009-01-01	29.8066
2010-01-01	31.1558
2011-01-01	36.3364
2012-01-01	35.9168
2013-01-01	37.9897
2014-01-01	36.5816