Year	Percent
1975-01-01	34.694600000000000
1976-01-01	35.889000000000000
1977-01-01	37.189500000000000
1978-01-01	36.675700000000000
1979-01-01	34.656400000000000
1980-01-01	35.021800000000000
1981-01-01	43.351000000000006
1982-01-01	32.508100000000000
1983-01-01	33.801300000000000
1984-01-01	44.579400000000000
1985-01-01	48.994000000000000
1986-01-01	64.619600000000000
1987-01-01	61.907700000000000
1988-01-01	53.751200000000000
1989-01-01	53.755600000000000
1990-01-01	47.949300000000000
1991-01-01	48.111700000000000
1992-01-01	52.501300000000000
1993-01-01	50.676300000000000
1994-01-01	49.482600000000000
1995-01-01	50.479600000000000
1996-01-01	50.656900000000000
1997-01-01	52.446300000000000
1998-01-01	61.620600000000000
1999-01-01	62.068500000000000
2000-01-01	55.916100000000000
2001-01-01	55.916100000000000
2002-01-01	55.916100000000000
2003-01-01	55.916100000000000
2004-01-01	53.497700000000000
2005-01-01	49.597000000000000
2006-01-01	50.667000000000000
2007-01-01	55.985000000000000
2008-01-01	60.060100000000000
2009-01-01	75.579700000000000
2010-01-01	73.564500000000000
2011-01-01	69.213800000000000
2012-01-01	68.012100000000000
2013-01-01	68.654100000000000
2014-01-01	71.675700000000000
2015-01-01	80.583600000000000