Year	Percent
1976-01-01	19.654200000000000
1977-01-01	19.864500000000000
1978-01-01	16.605999999999998
1979-01-01	13.749400000000000
1980-01-01	13.106900000000000
1981-01-01	11.049900000000000
1982-01-01	9.311770000000000
1983-01-01	8.375710000000000
1984-01-01	7.223839999999999
1985-01-01	5.956710000000000
1986-01-01	5.075330000000000
1987-01-01	5.207000000000001
1988-01-01	6.784450000000000
1989-01-01	8.029350000000000
1990-01-01	9.337520000000000
1991-01-01	9.401300000000000
1992-01-01	8.414880000000000
1993-01-01	24.204600000000000
1994-01-01	55.760900000000000
1995-01-01	72.129400000000000
1996-01-01	74.741100000000000
1997-01-01	76.171300000000000
1998-01-01	77.987800000000000
1999-01-01	79.425800000000000
2000-01-01	77.674500000000000
2001-01-01	75.767000000000000
2002-01-01	76.538200000000000
2003-01-01	78.015400000000000
2004-01-01	79.649600000000000
2005-01-01	81.669600000000000
2006-01-01	84.428200000000000
2007-01-01	86.979400000000000
2008-01-01	88.504100000000000
2009-01-01	89.843600000000000
2010-01-01	90.793500000000000
2011-01-01	91.955300000000000
2012-01-01	92.727600000000000
2013-01-01	92.954500000000000
2014-01-01	93.287200000000000
2015-01-01	93.665600000000000
2016-01-01	94.124600000000000