Year	Percent
1960-01-01	9.021400000000000
1961-01-01	8.978570000000000
1962-01-01	8.766919999999999
1963-01-01	8.680220000000000
1964-01-01	9.162610000000000
1965-01-01	10.560000000000000
1966-01-01	11.409200000000000
1967-01-01	12.573100000000000
1968-01-01	13.129700000000000
1969-01-01	13.825000000000000
1970-01-01	18.699200000000000
1971-01-01	23.483900000000000
1972-01-01	24.832600000000000
1973-01-01	24.764600000000000
1974-01-01	23.241500000000000
1975-01-01	23.046400000000000
1976-01-01	22.892700000000000
1977-01-01	21.604300000000000
1978-01-01	17.197100000000000
1979-01-01	10.917600000000000
1980-01-01	10.937500000000000
1981-01-01	13.152800000000000
1982-01-01	17.408200000000000
1983-01-01	18.417500000000000
1984-01-01	17.433100000000000
1985-01-01	17.324400000000000
1986-01-01	19.325100000000000
1987-01-01	20.674000000000000
1988-01-01	20.117600000000000
1989-01-01	18.976600000000000
1990-01-01	17.262400000000000
1991-01-01	18.246200000000000
1992-01-01	19.416100000000000
1993-01-01	17.996200000000000
1994-01-01	19.802200000000000
1995-01-01	21.565600000000000
1996-01-01	24.476700000000000
1997-01-01	25.536800000000000
1998-01-01	20.028000000000000
1999-01-01	25.930700000000000
2000-01-01	27.625000000000000
2001-01-01	31.505900000000000
2002-01-01	32.950100000000000
2003-01-01	30.744800000000000
2004-01-01	28.505300000000000
2005-01-01	31.242400000000000
2006-01-01	34.273800000000000
2007-01-01	36.376100000000000
2008-01-01	39.375700000000000
2009-01-01	45.555400000000000
2010-01-01	46.034200000000000
2011-01-01	43.501100000000000
2012-01-01	43.394700000000000
2013-01-01	43.625300000000000
2014-01-01	45.071700000000000
2015-01-01	44.470800000000000
2016-01-01	46.334900000000000