Year	Percent
1991-01-01	2.6665200000000002
1992-01-01	2.8624000000000000
1993-01-01	3.1200900000000003
1994-01-01	3.3997200000000000
1995-01-01	3.3084900000000000
1996-01-01	3.4297199999999997
1997-01-01	3.2551600000000000
1998-01-01	3.0004600000000000
1999-01-01	3.2358500000000000
2000-01-01	3.0501300000000000
2001-01-01	3.1657200000000000
2002-01-01	2.6993099999999997
2003-01-01	2.6526600000000000
2004-01-01	2.4928000000000000
2005-01-01	2.3905900000000000
2006-01-01	2.2884200000000000
2007-01-01	2.1653300000000000
2008-01-01	2.0597300000000000
2009-01-01	2.1798100000000000
2010-01-01	2.0799000000000000
2011-01-01	2.0757500000000000
2012-01-01	2.1904100000000000
2013-01-01	2.2774900000000002
2014-01-01	2.2352200000000000
2015-01-01	2.2173200000000000
2016-01-01	2.2148100000000000