Year	Percent
1962-01-01	15.294100000000000
1963-01-01	14.246400000000000
1964-01-01	14.267700000000000
1965-01-01	13.211400000000000
1966-01-01	13.094000000000001
1967-01-01	13.127100000000000
1968-01-01	13.273900000000000
1969-01-01	14.384800000000000
1970-01-01	4.562869999999999
1971-01-01	5.224850000000000
1972-01-01	5.417470000000000
1973-01-01	5.434220000000000
1974-01-01	5.951640000000000
1975-01-01	13.159600000000000
1976-01-01	14.480500000000000
1977-01-01	13.083500000000000
1978-01-01	13.234300000000000
1979-01-01	12.161600000000000
1980-01-01	13.378500000000000
1981-01-01	20.780800000000000
1982-01-01	22.917500000000000
1983-01-01	23.454400000000000
1984-01-01	22.418500000000000
1985-01-01	22.376400000000000
1986-01-01	22.463900000000000
1987-01-01	20.644900000000000
1988-01-01	18.915400000000000
1989-01-01	19.844100000000000
1990-01-01	22.320300000000000
1991-01-01	26.467900000000000
1992-01-01	28.010000000000000
1993-01-01	27.051600000000000
1994-01-01	25.865800000000000
1995-01-01	23.197900000000000
1996-01-01	21.826999999999998
1997-01-01	21.363200000000000
1998-01-01	19.978500000000000
1999-01-01	20.025900000000000
2000-01-01	23.605400000000000
2001-01-01	25.607800000000000
2002-01-01	24.365600000000000
2003-01-01	23.301900000000000
2004-01-01	21.970000000000000
2005-01-01	22.300400000000000
2006-01-01	25.044000000000000
2007-01-01	27.663000000000000
2008-01-01	31.311800000000000
2009-01-01	33.940300000000000
2010-01-01	35.538900000000000
2011-01-01	35.751200000000000
2012-01-01	34.743500000000000
2013-01-01	35.314300000000000
2014-01-01	39.248000000000005
2015-01-01	42.856400000000000
2016-01-01	41.961300000000000