Year	Percent
1960-01-01	25.254800000000000
1961-01-01	24.290200000000000
1962-01-01	23.717900000000000
1963-01-01	24.928000000000000
1964-01-01	24.997800000000000
1965-01-01	24.865900000000000
1966-01-01	25.011100000000000
1967-01-01	25.304600000000000
1968-01-01	26.199600000000000
1969-01-01	25.817700000000000
1970-01-01	24.993000000000002
1971-01-01	24.089700000000000
1972-01-01	24.027200000000000
1973-01-01	23.814800000000000
1974-01-01	24.164500000000000
1975-01-01	25.924800000000000
1976-01-01	26.870300000000000
1977-01-01	26.301200000000000
1978-01-01	25.234500000000000
1979-01-01	24.297200000000000
1980-01-01	25.176700000000000
1981-01-01	25.767600000000000
1982-01-01	25.235900000000000
1983-01-01	27.980100000000000
1984-01-01	31.481100000000000
1985-01-01	34.327700000000000
1986-01-01	36.172700000000000
1987-01-01	44.185700000000000
1988-01-01	52.664900000000000
1989-01-01	51.684000000000000
1990-01-01	50.858500000000000
1991-01-01	52.215400000000000
1992-01-01	52.003300000000000
1993-01-01	56.545500000000000
1994-01-01	54.730400000000000
1995-01-01	50.933600000000000
1996-01-01	51.893000000000000
1997-01-01	52.826000000000000
1998-01-01	53.723800000000000
1999-01-01	51.773300000000000
2000-01-01	46.927000000000000
2001-01-01	45.102200000000000
2002-01-01	45.730300000000000
2003-01-01	47.413800000000000
2004-01-01	49.117100000000000
2005-01-01	53.199300000000000
2006-01-01	56.589300000000000
2007-01-01	60.694900000000000
2008-01-01	65.319100000000000
2009-01-01	63.867500000000000
2010-01-01	53.894600000000000
2011-01-01	51.711300000000000
2012-01-01	50.496000000000000
2013-01-01	50.785900000000000
2014-01-01	51.812300000000000
2015-01-01	53.485800000000000
2016-01-01	55.413700000000000