Year	Percent
1972-01-01	9.140830000000001
1973-01-01	12.362900000000000
1974-01-01	13.736300000000000
1975-01-01	16.479200000000000
1976-01-01	18.062400000000000
1977-01-01	17.867700000000000
1978-01-01	14.083900000000000
1979-01-01	11.578600000000000
1980-01-01	10.824600000000000
1981-01-01	12.955600000000000
1982-01-01	13.028400000000000
1983-01-01	11.278100000000000
1984-01-01	11.274000000000001
1985-01-01	9.252790000000000
1986-01-01	7.653270000000000
1987-01-01	7.313670000000000
1988-01-01	6.020860000000000
1989-01-01	6.106390000000000
1990-01-01	7.757890000000000
1991-01-01	10.022500000000000
1992-01-01	12.850900000000000
1993-01-01	13.666800000000000
1994-01-01	13.362000000000000
1995-01-01	12.196800000000000
1996-01-01	10.007300000000000
1997-01-01	9.389400000000000
1998-01-01	10.479000000000001
1999-01-01	11.825400000000000
2000-01-01	13.412900000000000
2001-01-01	15.081900000000000
2002-01-01	17.298900000000000
2003-01-01	19.064900000000000
2004-01-01	19.888200000000000
2005-01-01	18.892000000000000
2006-01-01	18.889400000000000
2007-01-01	20.275800000000000
2008-01-01	23.341400000000000
2009-01-01	27.601800000000000
2010-01-01	25.930800000000000
2011-01-01	24.530700000000000
2012-01-01	28.234300000000000
2013-01-01	29.919000000000000
2014-01-01	29.346900000000000
2015-01-01	32.536800000000000
2016-01-01	30.425000000000000