Year	Percent
1960-01-01	36.477500000000000
1961-01-01	35.918500000000000
1962-01-01	37.609300000000000
1963-01-01	37.679300000000000
1964-01-01	33.532900000000000
1965-01-01	30.696900000000000
1966-01-01	30.737400000000000
1967-01-01	33.781400000000000
1968-01-01	37.249400000000000
1969-01-01	35.971300000000000
1970-01-01	35.624100000000000
1971-01-01	33.506300000000000
1972-01-01	32.881300000000000
1973-01-01	29.463200000000000
1974-01-01	27.494600000000000
1975-01-01	22.150600000000000
1976-01-01	20.953000000000003
1977-01-01	19.788900000000000
1978-01-01	19.681300000000000
1979-01-01	19.903900000000000
1980-01-01	20.222900000000000
1981-01-01	18.651900000000000
1982-01-01	16.746500000000000
1983-01-01	18.475100000000000
1984-01-01	19.678700000000000
1985-01-01	21.485200000000000
1986-01-01	22.716500000000000
1987-01-01	23.298100000000000
1988-01-01	25.977300000000000
1989-01-01	29.164300000000000
1990-01-01	32.593100000000000
1991-01-01	34.491900000000000
1992-01-01	37.659100000000000
1993-01-01	38.759100000000000
1994-01-01	37.622500000000000
1995-01-01	37.461999999999996
1996-01-01	36.495700000000000
1997-01-01	35.741200000000000
1998-01-01	35.853000000000000
1999-01-01	38.683100000000000
2000-01-01	40.573100000000000
2001-01-01	40.511500000000000
2002-01-01	43.768500000000000
2003-01-01	50.424700000000000
2004-01-01	53.328000000000000
2005-01-01	59.493900000000000
2006-01-01	77.125100000000000
2007-01-01	85.065700000000000
2008-01-01	89.291900000000000
2009-01-01	100.116000000000000
2010-01-01	95.126600000000000
2011-01-01	88.294300000000000
2012-01-01	85.193900000000000
2013-01-01	79.813100000000000
2014-01-01	78.649500000000000
2015-01-01	75.289300000000000
2016-01-01	68.685500000000000