Year	Percent
1967-01-01	22.320999999999998
1968-01-01	20.964400000000000
1969-01-01	22.597300000000000
1970-01-01	22.257800000000000
1971-01-01	23.334800000000000
1972-01-01	24.678400000000000
1973-01-01	24.007500000000000
1974-01-01	25.527700000000000
1975-01-01	24.588900000000000
1976-01-01	24.153200000000000
1977-01-01	25.335200000000000
1978-01-01	25.502700000000000
1979-01-01	27.480800000000000
1980-01-01	29.965100000000000
1981-01-01	30.386400000000000
1982-01-01	34.102900000000000
1983-01-01	38.935500000000000
1984-01-01	45.866500000000000
1985-01-01	57.828200000000000
1986-01-01	70.492100000000000
1987-01-01	88.870300000000000
1988-01-01	86.047100000000000
1989-01-01	91.724600000000000
1990-01-01	75.079900000000000
1991-01-01	70.674700000000000
1992-01-01	64.296500000000000
1993-01-01	42.472200000000000
1994-01-01	17.471400000000000
1995-01-01	14.601600000000000
1996-01-01	20.521400000000000
1997-01-01	23.849700000000000
1998-01-01	25.251500000000000
1999-01-01	25.574800000000000
2000-01-01	19.754700000000000
2001-01-01	21.448600000000000
2002-01-01	26.770000000000000
2003-01-01	32.651200000000000
2004-01-01	33.369300000000000
2005-01-01	32.802800000000000
2006-01-01	32.961800000000000
2007-01-01	37.219100000000000
2008-01-01	40.649300000000000
2009-01-01	42.534900000000000
2010-01-01	43.892200000000000
2011-01-01	44.093000000000000
2012-01-01	45.169900000000000
2013-01-01	50.396100000000000
2014-01-01	54.086700000000000
2015-01-01	57.181700000000000
2016-01-01	61.927600000000000