Year	Percent
1964-01-01	4.3437500000000000
1965-01-01	4.2726400000000000
1966-01-01	4.0888200000000000
1967-01-01	3.8635400000000000
1968-01-01	3.2448900000000003
1969-01-01	2.8780700000000000
1970-01-01	2.5432600000000000
1971-01-01	1.7901599999999998
1972-01-01	1.0806000000000000
1973-01-01	2.2064000000000000
1974-01-01	2.2064000000000000
1975-01-01	2.2064000000000000
1976-01-01	12.6533000000000000
1977-01-01	10.8080000000000000
1978-01-01	10.4773000000000000
1979-01-01	11.2376000000000000
1980-01-01	12.9977000000000000
1981-01-01	12.3741000000000000
1982-01-01	21.6779000000000000
1983-01-01	21.6779000000000000
1984-01-01	21.6779000000000000
1985-01-01	21.6779000000000000
1986-01-01	21.6779000000000000
1987-01-01	21.6779000000000000
1988-01-01	8.0861700000000000
1989-01-01	9.5238500000000000
1990-01-01	19.3807000000000000
1991-01-01	10.6429999999999990
1992-01-01	3.1791500000000000
1993-01-01	3.0619600000000000
1994-01-01	1.8844400000000001
1995-01-01	0.7815439999999999
1996-01-01	1.4189600000000000
1997-01-01	2.7737900000000000
1998-01-01	3.2345500000000000
1999-01-01	2.8186800000000000
2000-01-01	6.5685899999999995
2001-01-01	19.2687000000000000
2002-01-01	21.3263000000000000
2003-01-01	29.8633000000000000
2004-01-01	43.2599000000000000
2005-01-01	46.0538000000000000
2006-01-01	44.8847000000000000
2007-01-01	37.2035000000000000
2008-01-01	33.0526000000000000
2009-01-01	28.3004000000000000
2010-01-01	29.2340000000000000
2011-01-01	31.8983000000000000
2012-01-01	32.8583000000000000
2013-01-01	32.0903000000000000
2014-01-01	31.7242000000000000
2015-01-01	35.9268000000000000