Year	Percent
1975-01-01	35.289300000000000
1976-01-01	33.719900000000000
1977-01-01	32.031100000000000
1978-01-01	28.993600000000000
1979-01-01	38.657300000000000
1980-01-01	37.050400000000000
1981-01-01	33.133700000000000
1982-01-01	33.472600000000000
1983-01-01	35.473600000000000
1984-01-01	35.450200000000000
1985-01-01	35.444800000000000
1986-01-01	35.145600000000000
1987-01-01	37.919600000000000
1988-01-01	38.310400000000000
1989-01-01	39.244400000000000
1990-01-01	40.502900000000000
1991-01-01	43.982400000000000
1992-01-01	48.285800000000000
1993-01-01	48.636200000000000
1994-01-01	46.276900000000000
1995-01-01	51.040100000000000
1996-01-01	54.224300000000000
1997-01-01	55.641800000000000
1998-01-01	54.023700000000000
1999-01-01	55.763100000000000
2000-01-01	56.788400000000000
2001-01-01	56.376000000000005
2002-01-01	61.844500000000000
2003-01-01	65.616200000000000
2004-01-01	66.470400000000000
2005-01-01	70.934400000000000
2006-01-01	71.942700000000000
2007-01-01	73.171000000000000
2008-01-01	74.574400000000000
2009-01-01	73.755800000000000
2010-01-01	78.754400000000000
2011-01-01	79.921000000000000
2012-01-01	88.246300000000000
2013-01-01	91.415400000000000
2014-01-01	91.942200000000000
2015-01-01	93.046000000000000
2016-01-01	89.427600000000000