Year	Percent
1990-01-01	3.1860000000000004
1991-01-01	3.3675900000000003
1992-01-01	3.3471699999999998
1993-01-01	3.2832900000000000
1994-01-01	3.3068699999999995
1995-01-01	3.0244100000000000
1996-01-01	2.8661300000000000
1997-01-01	2.6298700000000000
1998-01-01	2.5038500000000000
1999-01-01	2.3636400000000000
2000-01-01	2.3754700000000000
2001-01-01	2.6241800000000000
2002-01-01	2.9336800000000000
2003-01-01	2.9297100000000000
2004-01-01	2.5472599999999996
2005-01-01	2.1977400000000000
2006-01-01	2.0204800000000000
2007-01-01	1.8055400000000001
2008-01-01	1.7531599999999998
2009-01-01	1.8414300000000000
2010-01-01	1.8424400000000000
2011-01-01	1.6440500000000000
2012-01-01	1.5984300000000000
2013-01-01	1.4801400000000000
2014-01-01	1.4494000000000000
2015-01-01	1.1369000000000000