Year	Percent
1990-01-01	2.2853900000000000
1991-01-01	2.2059500000000000
1992-01-01	2.2482599999999997
1993-01-01	2.3793400000000000
1994-01-01	2.4738599999999997
1995-01-01	2.4576599999999997
1996-01-01	2.4167799999999997
1997-01-01	2.3365500000000000
1998-01-01	2.2355300000000000
1999-01-01	2.1165200000000000
2000-01-01	2.0821600000000000
2001-01-01	2.0824599999999998
2002-01-01	2.1244000000000000
2003-01-01	2.1818200000000000
2004-01-01	2.1750400000000000
2005-01-01	2.1430599999999997
2006-01-01	2.0356700000000000
2007-01-01	1.9147299999999998
2008-01-01	1.8812700000000000
2009-01-01	1.9665700000000002
2010-01-01	1.8946000000000000
2011-01-01	1.8572099999999998
2012-01-01	1.8945400000000001
2013-01-01	1.9273000000000000
2014-01-01	1.9322700000000002
2015-01-01	1.9159500000000000
2016-01-01	1.9068400000000000