Year	Percent
1990-01-01	3.1713000000000000
1991-01-01	2.7687100000000000
1992-01-01	2.6343600000000000
1993-01-01	3.5570100000000000
1994-01-01	3.6795400000000003
1995-01-01	3.0261800000000000
1996-01-01	2.6216800000000000
1997-01-01	2.2314200000000000
1998-01-01	2.0262800000000000
1999-01-01	2.0505000000000000
2000-01-01	2.2125700000000000
2001-01-01	2.4519500000000000
2002-01-01	2.6528500000000000
2003-01-01	2.5368400000000000
2004-01-01	2.2001700000000000
2005-01-01	2.5241300000000000
2006-01-01	2.3837800000000000
2007-01-01	2.4869500000000000
2008-01-01	2.3177600000000000
2009-01-01	2.2849900000000000
2010-01-01	2.2505100000000000
2011-01-01	2.2332600000000000
2012-01-01	2.2705100000000000
2013-01-01	2.0876900000000003
2014-01-01	2.2518300000000000
2015-01-01	2.2494000000000000