Year	Percent
1973-01-01	14.854800000000000
1974-01-01	15.081400000000000
1975-01-01	16.544300000000000
1976-01-01	18.499000000000002
1977-01-01	20.826999999999998
1978-01-01	23.766400000000000
1979-01-01	24.120200000000000
1980-01-01	24.597500000000000
1981-01-01	25.255200000000000
1982-01-01	26.700200000000000
1983-01-01	26.580600000000000
1984-01-01	23.242200000000000
1985-01-01	20.679900000000000
1986-01-01	21.666999999999998
1987-01-01	25.979300000000000
1988-01-01	27.901200000000000
1989-01-01	29.720800000000000
1990-01-01	31.679100000000000
1991-01-01	30.361500000000000
1992-01-01	24.140800000000000
1993-01-01	16.089500000000000
1994-01-01	16.213800000000000
1995-01-01	12.842400000000000
1996-01-01	12.071400000000000
1997-01-01	10.907400000000000
1998-01-01	10.431300000000000
1999-01-01	10.945400000000000
2000-01-01	11.373100000000000
2001-01-01	11.800999999999998
2002-01-01	11.671300000000000
2003-01-01	11.899100000000000
2004-01-01	11.615300000000000
2005-01-01	11.448100000000000
2006-01-01	11.449100000000000
2007-01-01	11.116700000000000
2008-01-01	11.620800000000000
2009-01-01	12.347900000000000
2010-01-01	12.598400000000000
2011-01-01	13.861800000000000
2012-01-01	15.752700000000000
2013-01-01	17.128800000000000
2014-01-01	17.868700000000000
2015-01-01	19.019800000000000
2016-01-01	20.781200000000000