Year	Percent
1967-01-01	14.188600000000000
1968-01-01	13.643700000000000
1969-01-01	15.129000000000001
1970-01-01	15.091000000000000
1971-01-01	16.060600000000000
1972-01-01	17.235600000000000
1973-01-01	16.740800000000000
1974-01-01	17.625999999999998
1975-01-01	17.144200000000000
1976-01-01	17.427800000000000
1977-01-01	18.760800000000000
1978-01-01	19.001600000000000
1979-01-01	20.547500000000000
1980-01-01	22.114400000000000
1981-01-01	22.197100000000000
1982-01-01	24.410500000000000
1983-01-01	27.870100000000000
1984-01-01	33.860400000000000
1985-01-01	42.886800000000000
1986-01-01	52.393800000000000
1987-01-01	62.066100000000000
1988-01-01	54.303100000000000
1989-01-01	57.874800000000000
1990-01-01	50.357600000000000
1991-01-01	51.251900000000000
1992-01-01	47.849500000000000
1993-01-01	31.234000000000000
1994-01-01	11.752500000000000
1995-01-01	9.340410000000000
1996-01-01	14.106000000000000
1997-01-01	17.379700000000000
1998-01-01	18.350900000000000
1999-01-01	17.459700000000000
2000-01-01	12.343500000000000
2001-01-01	13.300200000000000
2002-01-01	19.678700000000000
2003-01-01	26.877200000000000
2004-01-01	28.572200000000000
2005-01-01	28.172400000000000
2006-01-01	28.236000000000000
2007-01-01	32.075400000000000
2008-01-01	33.730400000000000
2009-01-01	35.286400000000000
2010-01-01	37.339200000000000
2011-01-01	37.505400000000000
2012-01-01	38.583700000000000
2013-01-01	44.165600000000000
2014-01-01	48.503400000000000
2015-01-01	51.284000000000000
2016-01-01	56.353800000000000