Year	Percent
1976-01-01	2.2986299999999997
1977-01-01	2.2081700000000000
1978-01-01	1.9744900000000000
1979-01-01	2.0763599999999998
1980-01-01	2.3794400000000000
1981-01-01	2.6447300000000000
1982-01-01	2.4788799999999998
1983-01-01	2.4298200000000000
1984-01-01	2.0694300000000000
1985-01-01	1.8664700000000000
1986-01-01	1.6071400000000000
1987-01-01	1.7225000000000000
1988-01-01	2.1798900000000003
1989-01-01	2.7503300000000000
1990-01-01	3.7294099999999997
1991-01-01	4.1593900000000000
1992-01-01	3.9577500000000000
1993-01-01	10.2343000000000000
1994-01-01	16.2361000000000000
1995-01-01	19.5908000000000000
1996-01-01	21.5772000000000000
1997-01-01	23.9383000000000000
1998-01-01	25.3427000000000000
1999-01-01	29.3233000000000000
2000-01-01	34.2664000000000000
2001-01-01	34.1297000000000000
2002-01-01	35.2000000000000000
2003-01-01	36.3931000000000000
2004-01-01	38.1393000000000000
2005-01-01	38.5622000000000000
2006-01-01	40.4694000000000000
2007-01-01	42.3953000000000000
2008-01-01	46.5988000000000000
2009-01-01	53.9376000000000000
2010-01-01	58.6105000000000000
2011-01-01	61.8542000000000000
2012-01-01	63.9811000000000000
2013-01-01	62.6413000000000000
2014-01-01	62.6020000000000000
2015-01-01	61.1233000000000000
2016-01-01	59.8940000000000000