Year	Percent
1986-01-01	68.2671131942054
1987-01-01	67.6595506338319
1988-01-01	64.7044586077313
1989-01-01	61.7828288436234
1990-01-01	64.5308683558825
1991-01-01	63.4758283198395
1992-01-01	61.4989053425600
1993-01-01	60.6389505638146
1994-01-01	62.0331205466179
1995-01-01	62.9838381158198
1996-01-01	63.3615523710318
1997-01-01	63.7409070487146
1998-01-01	62.0072059526846
1999-01-01	59.2124441613053
2000-01-01	59.5194927325698
2001-01-01	59.7307538596222
2002-01-01	60.5087058154423
2003-01-01	59.5025852822424
2004-01-01	58.6477336516844
2005-01-01	59.1601379432870
2006-01-01	61.4957412940992
2007-01-01	61.7505212874645
2008-01-01	59.8659327343584
2009-01-01	58.0852844885830
2010-01-01	57.2749142551602
2011-01-01	56.0608483094972
2012-01-01	56.2349787287694
2013-01-01	56.1049157361042
2014-01-01	57.8109051276214
2015-01-01	59.1632773059530
2016-01-01	60.0087668365398
2017-01-01	61.2928931240878