Year	Percent
1980-01-01	2.1072100000000000
1981-01-01	1.6833300000000000
1982-01-01	1.3240600000000000
1983-01-01	1.2726600000000001
1984-01-01	1.2623900000000000
1985-01-01	1.0897900000000000
1986-01-01	1.0581900000000000
1987-01-01	1.0359000000000000
1988-01-01	1.6706400000000001
1989-01-01	1.3821800000000000
1990-01-01	0.9952190000000001
1991-01-01	2.0665600000000000
1992-01-01	1.4374799999999999
1993-01-01	1.7813100000000000
1994-01-01	2.6876200000000000
1995-01-01	2.5258700000000003
1996-01-01	4.6301200000000000
1997-01-01	4.0202100000000000
1998-01-01	4.1258800000000000
1999-01-01	3.4930400000000000
2000-01-01	2.8222300000000000
2001-01-01	3.3826000000000000
2002-01-01	1.8623700000000000
2003-01-01	2.4280400000000000
2004-01-01	2.4461200000000000
2005-01-01	2.7543900000000003
2006-01-01	4.0493900000000000
2007-01-01	4.3735000000000000
2008-01-01	3.8626000000000000
2009-01-01	4.8584500000000000
2010-01-01	5.6226600000000000
2011-01-01	5.5619800000000000
2012-01-01	5.9791500000000000
2013-01-01	6.0404200000000000
2014-01-01	7.5973100000000000
2015-01-01	9.2378700000000000
2016-01-01	12.4511000000000000