Year	Percent
1968-01-01	1.6926200000000000
1969-01-01	1.6383600000000000
1970-01-01	1.3464000000000000
1971-01-01	1.3701000000000000
1972-01-01	1.2450900000000000
1973-01-01	0.5430380000000000
1974-01-01	0.4426900000000000
1975-01-01	0.9680280000000001
1976-01-01	1.2645899999999999
1977-01-01	1.2947200000000000
1978-01-01	0.9750870000000000
1979-01-01	1.0959900000000000
1980-01-01	1.5713500000000000
1981-01-01	1.8392300000000000
1982-01-01	1.3268300000000000
1983-01-01	1.2181799999999998
1984-01-01	1.4125200000000000
1985-01-01	1.2139000000000000
1986-01-01	0.9289410000000000
1987-01-01	1.1530700000000000
1988-01-01	1.3190800000000000
1989-01-01	1.5974600000000000
1990-01-01	2.4504900000000003
1991-01-01	2.9214800000000000
1992-01-01	3.2578300000000000
1993-01-01	3.1653900000000000
1994-01-01	3.0637100000000000
1995-01-01	3.3166500000000000
1996-01-01	3.2518599999999998
1997-01-01	2.9612700000000003
1998-01-01	1.9007200000000000
1999-01-01	1.1166399999999999
2000-01-01	1.5963600000000000
2001-01-01	2.4422099999999998
2002-01-01	2.6702100000000000
2003-01-01	2.1595600000000000
2004-01-01	1.8626500000000000
2005-01-01	1.9431599999999998
2006-01-01	2.1386500000000000
2007-01-01	3.2290099999999997
2008-01-01	3.3949500000000000
2009-01-01	2.5933000000000000
2010-01-01	3.0067600000000000
2011-01-01	3.6746500000000000
2012-01-01	4.2352500000000000
2013-01-01	5.5758700000000000
2014-01-01	6.5089200000000000
2015-01-01	6.2526199999999990
2016-01-01	7.1443699999999990