Year	Percent
1975-01-01	80.362100000000000
1976-01-01	53.806600000000000
1977-01-01	51.436800000000000
1978-01-01	46.235500000000000
1979-01-01	40.222800000000000
1980-01-01	37.687100000000000
1981-01-01	39.079500000000000
1982-01-01	39.890500000000000
1983-01-01	41.578800000000000
1984-01-01	40.061700000000000
1985-01-01	38.140400000000000
1986-01-01	37.456800000000000
1987-01-01	41.711000000000006
1988-01-01	44.063500000000000
1989-01-01	45.580300000000000
1990-01-01	47.110300000000000
1991-01-01	47.312100000000000
1992-01-01	49.935800000000000
1993-01-01	50.751500000000000
1994-01-01	47.199000000000000
1995-01-01	53.006600000000000
1996-01-01	56.966800000000000
1997-01-01	68.166700000000000
1998-01-01	67.001900000000000
1999-01-01	70.543500000000000
2000-01-01	71.688800000000000
2001-01-01	78.371800000000000
2002-01-01	80.758000000000000
2003-01-01	80.146500000000000
2004-01-01	75.621600000000000
2005-01-01	71.014500000000000
2006-01-01	71.820300000000000
2007-01-01	73.106000000000010
2008-01-01	81.240300000000000
2009-01-01	94.562200000000000
2010-01-01	100.288000000000000
2011-01-01	98.292600000000000
2012-01-01	90.836700000000000
2013-01-01	89.784600000000000
2014-01-01	81.103900000000000
2015-01-01	71.020600000000000
2016-01-01	62.598600000000000