Year	Percent
1964-01-01	60.606200000000000
1965-01-01	60.312200000000000
1966-01-01	60.077600000000000
1967-01-01	60.485600000000000
1968-01-01	50.463400000000000
1969-01-01	45.564100000000000
1970-01-01	43.946800000000000
1971-01-01	44.611000000000004
1972-01-01	46.696800000000000
1973-01-01	55.913700000000000
1974-01-01	55.913700000000000
1975-01-01	55.913700000000000
1976-01-01	172.018000000000000
1977-01-01	93.172300000000000
1978-01-01	102.512999999999990
1979-01-01	103.315000000000000
1980-01-01	104.272000000000000
1981-01-01	111.482000000000010
1982-01-01	186.606000000000000
1983-01-01	186.606000000000000
1984-01-01	186.606000000000000
1985-01-01	186.606000000000000
1986-01-01	186.606000000000000
1987-01-01	186.606000000000000
1988-01-01	46.776300000000000
1989-01-01	59.872500000000000
1990-01-01	61.489000000000000
1991-01-01	42.586999999999996
1992-01-01	35.662600000000000
1993-01-01	40.779900000000000
1994-01-01	44.749100000000000
1995-01-01	50.255700000000000
1996-01-01	56.341900000000000
1997-01-01	58.043400000000000
1998-01-01	65.109100000000000
1999-01-01	75.590200000000000
2000-01-01	83.145800000000000
2001-01-01	83.764100000000000
2002-01-01	78.385200000000000
2003-01-01	76.857000000000000
2004-01-01	73.495400000000000
2005-01-01	70.717200000000000
2006-01-01	67.527300000000000
2007-01-01	71.370900000000000
2008-01-01	67.754300000000000
2009-01-01	63.206900000000000
2010-01-01	70.205200000000000
2011-01-01	80.575700000000000
2012-01-01	82.188900000000000
2013-01-01	85.796700000000000
2014-01-01	91.883900000000000
2015-01-01	93.956300000000000
2016-01-01	97.006900000000000