Year	Percent
1960-01-01	18.3582000000000000
1961-01-01	17.9131000000000000
1962-01-01	18.7763000000000000
1963-01-01	19.3909000000000000
1964-01-01	20.8067000000000000
1965-01-01	21.3717000000000000
1966-01-01	21.2792000000000000
1967-01-01	20.7601000000000000
1968-01-01	20.0548000000000000
1969-01-01	18.7309000000000000
1970-01-01	11.6051000000000000
1971-01-01	11.9467000000000000
1972-01-01	13.1811000000000000
1973-01-01	13.2359000000000000
1974-01-01	12.1647000000000000
1975-01-01	14.3948000000000000
1976-01-01	16.1423000000000000
1977-01-01	16.8824000000000000
1978-01-01	12.1405000000000000
1979-01-01	12.3277000000000000
1980-01-01	10.3227000000000000
1981-01-01	9.6315400000000000
1982-01-01	8.7579600000000000
1983-01-01	7.4337100000000005
1984-01-01	6.3387000000000000
1985-01-01	7.2545699999999990
1986-01-01	7.0359000000000000
1987-01-01	7.5999800000000000
1988-01-01	8.1454200000000000
1989-01-01	8.8648100000000000
1990-01-01	8.4426899999999990
1991-01-01	8.0843700000000000
1992-01-01	9.9536500000000000
1993-01-01	11.1622000000000000
1994-01-01	11.3282000000000000
1995-01-01	11.8620000000000000
1996-01-01	11.1067000000000000
1997-01-01	12.8972000000000000
1998-01-01	13.6650000000000000
1999-01-01	13.6701000000000000
2000-01-01	14.2649000000000000
2001-01-01	14.7569000000000000
2002-01-01	15.7534000000000000
2003-01-01	17.3365000000000000
2004-01-01	18.0185000000000000
2005-01-01	17.7189000000000000
2006-01-01	18.4891000000000000
2007-01-01	21.5206000000000000
2008-01-01	23.8335000000000000
2009-01-01	26.3111000000000000
2010-01-01	26.5755000000000000
2011-01-01	27.2552000000000000
2012-01-01	27.5758000000000000
2013-01-01	27.2919000000000000
2014-01-01	28.9600000000000000
2015-01-01	31.3345000000000000
2016-01-01	32.0643000000000000