Year	Percent
1980-01-01	2.4741900000000000
1981-01-01	2.2491300000000000
1982-01-01	2.5059000000000000
1983-01-01	2.8611500000000000
1984-01-01	2.6532200000000000
1985-01-01	4.2970400000000000
1986-01-01	5.7066800000000000
1987-01-01	5.9852300000000005
1988-01-01	4.3708200000000000
1989-01-01	3.5006300000000000
1990-01-01	3.1488500000000000
1991-01-01	2.9107500000000000
1992-01-01	2.2544000000000000
1993-01-01	3.5309000000000000
1994-01-01	3.8838800000000004
1995-01-01	3.7555600000000000
1996-01-01	3.4249400000000003
1997-01-01	3.0853200000000003
1998-01-01	3.2651000000000000
1999-01-01	2.3963600000000000
2000-01-01	2.0034799999999997
2001-01-01	1.6474600000000000
2002-01-01	1.7272599999999998
2003-01-01	1.5745000000000000
2004-01-01	1.3564200000000002
2005-01-01	1.1989700000000000
2006-01-01	1.0810100000000000
2007-01-01	1.1088000000000000
2008-01-01	0.8992209999999999
2009-01-01	1.0264100000000000
2010-01-01	0.8098069999999999
2011-01-01	0.8893000000000000
2012-01-01	0.7423820000000000
2013-01-01	0.6658850000000001
2014-01-01	0.2960960000000000
2015-01-01	0.3073860000000000
2016-01-01	0.3533100000000000