Year	Percent
1973-01-01	20.534200000000000
1974-01-01	20.712300000000000
1975-01-01	22.686400000000000
1976-01-01	25.149500000000000
1977-01-01	26.101999999999997
1978-01-01	27.316300000000000
1979-01-01	28.235600000000000
1980-01-01	30.749800000000000
1981-01-01	31.595100000000000
1982-01-01	33.299300000000000
1983-01-01	33.548500000000000
1984-01-01	30.155100000000000
1985-01-01	25.586000000000000
1986-01-01	21.009000000000000
1987-01-01	18.265400000000000
1988-01-01	18.919100000000000
1989-01-01	20.044000000000000
1990-01-01	21.090900000000000
1991-01-01	21.822500000000000
1992-01-01	23.037600000000000
1993-01-01	27.341300000000000
1994-01-01	31.904700000000000
1995-01-01	37.500100000000000
1996-01-01	46.839600000000000
1997-01-01	56.461100000000000
1998-01-01	57.521800000000000
1999-01-01	50.725500000000000
2000-01-01	48.183300000000000
2001-01-01	48.377400000000000
2002-01-01	46.670000000000000
2003-01-01	45.418100000000000
2004-01-01	44.670200000000000
2005-01-01	42.626999999999995
2006-01-01	38.540200000000000
2007-01-01	35.002300000000000
2008-01-01	37.961800000000000
2009-01-01	43.577400000000000
2010-01-01	42.864700000000000
2011-01-01	45.022800000000000
2012-01-01	46.275300000000000
2013-01-01	47.379900000000000
2014-01-01	50.439600000000000
2015-01-01	54.204900000000000
2016-01-01	55.486900000000000