Year	Percent
1960-01-01	16.383400000000000
1961-01-01	15.283200000000000
1962-01-01	15.697100000000000
1963-01-01	16.754100000000000
1964-01-01	16.050600000000000
1965-01-01	17.164100000000000
1966-01-01	17.024000000000000
1967-01-01	16.669800000000000
1968-01-01	16.798400000000000
1969-01-01	16.433500000000000
1970-01-01	15.727600000000000
1971-01-01	16.687400000000000
1972-01-01	18.503300000000000
1973-01-01	18.934100000000000
1974-01-01	18.309000000000000
1975-01-01	18.388100000000000
1976-01-01	16.654400000000000
1977-01-01	14.844300000000000
1978-01-01	12.913200000000000
1979-01-01	9.211030000000001
1980-01-01	11.198200000000000
1981-01-01	13.691300000000000
1982-01-01	15.475400000000000
1983-01-01	17.683800000000000
1984-01-01	16.817000000000000
1985-01-01	14.786400000000000
1986-01-01	12.735800000000000
1987-01-01	11.319000000000000
1988-01-01	9.045520000000000
1989-01-01	5.726840000000000
1990-01-01	5.004030000000000
1991-01-01	5.724080000000001
1992-01-01	8.240750000000000
1993-01-01	9.899400000000000
1994-01-01	11.671400000000000
1995-01-01	14.333800000000000
1996-01-01	18.589700000000000
1997-01-01	22.497500000000000
1998-01-01	27.087000000000000
1999-01-01	29.040700000000000
2000-01-01	27.732900000000000
2001-01-01	25.471000000000000
2002-01-01	22.679500000000000
2003-01-01	20.738300000000000
2004-01-01	18.404600000000000
2005-01-01	18.228300000000000
2006-01-01	17.517500000000000
2007-01-01	18.714300000000000
2008-01-01	22.490400000000000
2009-01-01	25.255700000000000
2010-01-01	23.790900000000000
2011-01-01	25.225200000000000
2012-01-01	30.269700000000000
2013-01-01	35.445700000000000
2014-01-01	38.197800000000000
2015-01-01	40.763100000000000
2016-01-01	41.203400000000000