Year	Percent
1975-01-01	98.579000000000000
1976-01-01	58.203800000000000
1977-01-01	49.945700000000000
1978-01-01	45.461999999999996
1979-01-01	41.415600000000000
1980-01-01	38.902700000000000
1981-01-01	39.319200000000000
1982-01-01	40.535300000000000
1983-01-01	43.520300000000000
1984-01-01	43.284900000000000
1985-01-01	40.659000000000000
1986-01-01	38.765900000000000
1987-01-01	42.769000000000000
1988-01-01	45.494800000000000
1989-01-01	47.710100000000000
1990-01-01	49.291800000000000
1991-01-01	51.530700000000000
1992-01-01	55.951300000000000
1993-01-01	56.683800000000000
1994-01-01	55.629900000000000
1995-01-01	65.055200000000000
1996-01-01	63.896100000000000
1997-01-01	63.067000000000000
1998-01-01	63.266400000000000
1999-01-01	72.097200000000000
2000-01-01	76.169400000000000
2001-01-01	83.683400000000000
2002-01-01	86.880200000000000
2003-01-01	91.282800000000000
2004-01-01	93.664400000000000
2005-01-01	90.108600000000000
2006-01-01	88.280600000000000
2007-01-01	85.742300000000000
2008-01-01	90.140900000000000
2009-01-01	95.426100000000000
2010-01-01	96.875700000000000
2011-01-01	98.569000000000000
2012-01-01	95.205400000000000
2013-01-01	98.200600000000000
2014-01-01	92.667200000000000
2015-01-01	89.923300000000000
2016-01-01	85.579500000000000