Year	Percent
1972-01-01	2.7589400000000000
1973-01-01	6.2711200000000000
1974-01-01	7.7750699999999995
1975-01-01	9.3592300000000000
1976-01-01	11.7811000000000000
1977-01-01	12.2540000000000010
1978-01-01	15.1637000000000000
1979-01-01	12.8016000000000000
1980-01-01	11.9356000000000000
1981-01-01	11.6744000000000000
1982-01-01	10.9969000000000000
1983-01-01	9.7653000000000000
1984-01-01	9.8530100000000010
1985-01-01	8.3874100000000010
1986-01-01	5.9412900000000000
1987-01-01	3.8928900000000000
1988-01-01	2.4501400000000000
1989-01-01	1.7361200000000000
1990-01-01	0.8968079999999999
1991-01-01	2.1886500000000000
1992-01-01	2.0006400000000000
1993-01-01	2.0354300000000000
1994-01-01	1.4031300000000000
1995-01-01	1.3174800000000000
1996-01-01	1.8343500000000000
1997-01-01	2.8424500000000000
1998-01-01	3.6911800000000000
1999-01-01	5.4347699999999990
2000-01-01	6.3178500000000000
2001-01-01	7.2169500000000000
2002-01-01	8.9469400000000000
2003-01-01	10.4497000000000000
2004-01-01	12.0359000000000000
2005-01-01	10.8421000000000000
2006-01-01	10.8751000000000000
2007-01-01	8.7142800000000000
2008-01-01	8.0888500000000000
2009-01-01	8.4625700000000000
2010-01-01	8.8326900000000000
2011-01-01	9.7019200000000000
2012-01-01	12.7891000000000000
2013-01-01	11.0708000000000000
2014-01-01	12.2402000000000000
2015-01-01	14.7143000000000000
2016-01-01	20.7236000000000000