Year	Percent
1976-01-01	31.768100000000000
1977-01-01	26.019400000000000
1978-01-01	28.189200000000000
1979-01-01	29.781600000000000
1980-01-01	26.983700000000000
1981-01-01	26.983700000000000
1982-01-01	36.779600000000000
1983-01-01	36.833200000000000
1984-01-01	35.114700000000000
1985-01-01	36.022900000000000
1986-01-01	34.041500000000000
1987-01-01	31.778300000000000
1988-01-01	33.036300000000000
1989-01-01	34.504300000000000
1990-01-01	34.901700000000000
1991-01-01	37.563100000000000
1992-01-01	37.392600000000000
1993-01-01	37.340100000000000
1994-01-01	37.910600000000000
1995-01-01	37.558200000000000
1996-01-01	39.595400000000000
1997-01-01	43.329600000000000
1998-01-01	46.688700000000000
1999-01-01	47.117900000000000
2000-01-01	47.536800000000000
2001-01-01	55.030900000000000
2002-01-01	57.757100000000000
2003-01-01	58.948400000000000
2004-01-01	63.051900000000000
2005-01-01	64.378500000000000
2006-01-01	57.196999999999996
2007-01-01	56.087900000000000
2008-01-01	61.171200000000000
2009-01-01	65.369400000000000
2010-01-01	64.725700000000000
2011-01-01	60.379000000000000
2012-01-01	56.054400000000000
2013-01-01	55.573700000000000
2014-01-01	54.679100000000000
2015-01-01	55.959600000000000
2016-01-01	57.543700000000000