Year	Percent
1973-01-01	8.003280000000000
1974-01-01	9.235350000000000
1975-01-01	10.301600000000000
1976-01-01	11.554100000000000
1977-01-01	13.516800000000000
1978-01-01	15.189900000000000
1979-01-01	14.826600000000000
1980-01-01	14.378500000000000
1981-01-01	15.266900000000000
1982-01-01	12.982300000000000
1983-01-01	11.880700000000000
1984-01-01	5.683430000000000
1985-01-01	5.898160000000000
1986-01-01	10.555700000000000
1987-01-01	13.334900000000000
1988-01-01	15.018700000000000
1989-01-01	17.186800000000000
1990-01-01	19.959300000000000
1991-01-01	24.394500000000000
1992-01-01	31.279300000000000
1993-01-01	39.489500000000000
1994-01-01	45.142900000000000
1995-01-01	46.254600000000000
1996-01-01	50.546100000000000
1997-01-01	56.214400000000000
1998-01-01	61.822900000000000
1999-01-01	65.509300000000000
2000-01-01	61.803999999999995
2001-01-01	58.233999999999995
2002-01-01	54.418500000000000
2003-01-01	50.947400000000000
2004-01-01	46.606900000000000
2005-01-01	43.214200000000000
2006-01-01	37.050500000000000
2007-01-01	35.090100000000000
2008-01-01	32.538400000000000
2009-01-01	34.194100000000000
2010-01-01	34.201900000000000
2011-01-01	34.585600000000000
2012-01-01	36.337700000000000
2013-01-01	38.378000000000000
2014-01-01	41.710000000000000
2015-01-01	48.480800000000000
2016-01-01	54.901300000000000