Year	Percent
1973-01-01	9.372860000000001
1974-01-01	10.234000000000000
1975-01-01	11.701600000000000
1976-01-01	11.676100000000000
1977-01-01	9.222990000000000
1978-01-01	9.623450000000000
1979-01-01	11.381700000000000
1980-01-01	10.982600000000000
1981-01-01	11.964600000000000
1982-01-01	11.928400000000000
1983-01-01	11.587800000000000
1984-01-01	10.710200000000000
1985-01-01	10.231000000000000
1986-01-01	9.810180000000000
1987-01-01	9.293730000000000
1988-01-01	10.592500000000000
1989-01-01	11.180700000000000
1990-01-01	13.004800000000000
1991-01-01	15.813500000000000
1992-01-01	16.146500000000000
1993-01-01	15.051100000000000
1994-01-01	15.099100000000000
1995-01-01	13.688200000000000
1996-01-01	12.569600000000000
1997-01-01	12.009700000000000
1998-01-01	11.743100000000000
1999-01-01	11.300999999999998
2000-01-01	11.166200000000000
2001-01-01	9.871500000000000
2002-01-01	10.375100000000000
2003-01-01	12.993500000000000
2004-01-01	15.521300000000000
2005-01-01	16.997600000000000
2006-01-01	18.644500000000000
2007-01-01	20.561000000000000
2008-01-01	21.046800000000000
2009-01-01	20.548400000000000
2010-01-01	20.846900000000000
2011-01-01	22.654600000000000
2012-01-01	23.624400000000000
2013-01-01	23.921999999999997
2014-01-01	25.048400000000000
2015-01-01	24.642100000000000
2016-01-01	24.542400000000000