Year	Percent
1962-01-01	11.387800000000000
1963-01-01	10.045500000000000
1964-01-01	7.681160000000000
1965-01-01	5.709600000000000
1966-01-01	6.081950000000000
1967-01-01	7.261189999999999
1968-01-01	8.639600000000000
1969-01-01	8.801520000000000
1970-01-01	9.808190000000000
1971-01-01	10.335300000000000
1972-01-01	11.042800000000000
1973-01-01	13.981000000000000
1974-01-01	15.513800000000000
1975-01-01	17.295000000000000
1976-01-01	18.549300000000000
1977-01-01	20.406400000000000
1978-01-01	21.235500000000000
1979-01-01	19.131400000000000
1980-01-01	21.836900000000000
1981-01-01	23.462400000000000
1982-01-01	24.805900000000000
1983-01-01	23.152600000000000
1984-01-01	23.469100000000000
1985-01-01	26.060800000000000
1986-01-01	22.998300000000000
1987-01-01	23.947100000000000
1988-01-01	24.727600000000000
1989-01-01	24.313500000000000
1990-01-01	22.057300000000000
1991-01-01	21.102200000000000
1992-01-01	21.102200000000000
1993-01-01	21.102200000000000
1994-01-01	21.102200000000000
1995-01-01	21.102200000000000
1996-01-01	21.102200000000000
1997-01-01	21.102200000000000
1998-01-01	21.102200000000000
1999-01-01	21.102200000000000
2000-01-01	21.102200000000000
2001-01-01	21.102200000000000
2002-01-01	21.102200000000000
2003-01-01	21.102200000000000
2004-01-01	21.102200000000000
2005-01-01	26.213400000000000
2006-01-01	20.394500000000000
2007-01-01	22.341900000000000
2008-01-01	23.864200000000000
2009-01-01	26.764700000000000
2010-01-01	24.493200000000000
2011-01-01	23.482700000000000
2012-01-01	25.548000000000002