Year	Percent
1965-01-01	19.071300000000000
1966-01-01	19.075200000000000
1967-01-01	19.144500000000000
1968-01-01	18.903100000000000
1969-01-01	19.071100000000000
1970-01-01	19.602800000000000
1971-01-01	20.568400000000000
1972-01-01	21.454700000000000
1973-01-01	22.426200000000000
1974-01-01	24.162700000000000
1975-01-01	24.038700000000000
1976-01-01	21.263700000000000
1977-01-01	20.643900000000000
1978-01-01	22.954600000000000
1979-01-01	23.645400000000000
1980-01-01	24.364400000000000
1981-01-01	25.866200000000000
1982-01-01	28.496700000000000
1983-01-01	30.769000000000002
1984-01-01	31.973100000000000
1985-01-01	37.037500000000000
1986-01-01	35.923700000000000
1987-01-01	26.280500000000000
1988-01-01	27.756400000000000
1989-01-01	28.843600000000000
1990-01-01	23.160300000000000
1991-01-01	16.824800000000000
1992-01-01	17.430300000000000
1993-01-01	19.262800000000000
1994-01-01	24.761100000000000
1995-01-01	30.758800000000000
1996-01-01	34.921600000000000
1997-01-01	37.681200000000000
1998-01-01	39.909200000000000
1999-01-01	41.972800000000000
2000-01-01	43.501400000000000
2001-01-01	42.065600000000000
2002-01-01	39.567100000000000
2003-01-01	39.623300000000000
2004-01-01	40.615100000000000
2005-01-01	40.455500000000000
2006-01-01	40.890700000000000
2007-01-01	41.127900000000000
2008-01-01	41.939400000000000
2009-01-01	42.521900000000000
2010-01-01	40.006700000000000
2011-01-01	38.475900000000000
2012-01-01	38.599900000000000
2013-01-01	40.003400000000000
2014-01-01	41.496300000000000
2015-01-01	41.132600000000000
2016-01-01	42.257400000000000