Year	Percent
1998-01-01	16.31007646190750
1999-01-01	15.70857946004360
2000-01-01	14.50038959835180
2001-01-01	12.95753066190010
2002-01-01	12.20616506118030
2003-01-01	11.61015427521720
2004-01-01	10.47694773588110
2005-01-01	10.03903732557260
2006-01-01	8.77092053371018
2007-01-01	7.83655983501541
2008-01-01	8.49501951083722
2009-01-01	9.21896988057733
2010-01-01	9.59342822488976
2011-01-01	9.53532706558708
2012-01-01	11.82096821625300
2013-01-01	13.05884320638750
2014-01-01	13.79063003060620
2015-01-01	12.68685549801410
2016-01-01	12.77180754105180
2017-01-01	12.38663621807350