Year	Percent
1960-01-01	8.3811700000000000
1961-01-01	8.5783300000000010
1962-01-01	9.5837500000000000
1963-01-01	10.5433000000000000
1964-01-01	11.3135000000000000
1965-01-01	12.1935000000000000
1966-01-01	13.1231000000000000
1967-01-01	12.9889000000000000
1968-01-01	12.6871000000000000
1969-01-01	11.7011000000000000
1970-01-01	7.2348000000000000
1971-01-01	7.7419100000000010
1972-01-01	8.5221400000000000
1973-01-01	8.5519100000000010
1974-01-01	7.7813600000000000
1975-01-01	9.0227700000000000
1976-01-01	9.9908600000000010
1977-01-01	10.0581000000000000
1978-01-01	6.8539800000000000
1979-01-01	6.6056100000000000
1980-01-01	5.3158699999999990
1981-01-01	4.7698500000000000
1982-01-01	4.4268300000000010
1983-01-01	3.6903699999999997
1984-01-01	2.8196700000000000
1985-01-01	3.2679200000000000
1986-01-01	3.2426300000000000
1987-01-01	3.4233500000000000
1988-01-01	3.5175800000000000
1989-01-01	4.6508900000000000
1990-01-01	5.3004500000000000
1991-01-01	5.5864500000000000
1992-01-01	6.9438900000000000
1993-01-01	7.7203100000000004
1994-01-01	7.8513000000000000
1995-01-01	8.0228300000000000
1996-01-01	7.5298800000000000
1997-01-01	8.9865800000000000
1998-01-01	9.6169100000000000
1999-01-01	9.2257400000000000
2000-01-01	8.7669000000000000
2001-01-01	9.4085200000000000
2002-01-01	10.8050000000000000
2003-01-01	11.7646000000000000
2004-01-01	12.2436000000000000
2005-01-01	12.3286000000000000
2006-01-01	13.4194000000000000
2007-01-01	16.3099000000000000
2008-01-01	18.6563000000000000
2009-01-01	20.7958000000000000
2010-01-01	20.7338000000000000
2011-01-01	21.2406000000000000
2012-01-01	21.4475000000000000
2013-01-01	21.2217000000000000
2014-01-01	22.8611000000000000
2015-01-01	24.9294000000000000
2016-01-01	25.5212000000000000