Year	Percent
1960-01-01	23.870000000000000
1961-01-01	22.016100000000000
1962-01-01	19.497500000000000
1963-01-01	18.637400000000000
1964-01-01	18.329700000000000
1965-01-01	16.255100000000000
1966-01-01	14.732500000000000
1967-01-01	15.547900000000000
1968-01-01	17.031300000000000
1969-01-01	16.927400000000000
1970-01-01	12.848600000000000
1971-01-01	13.170600000000000
1972-01-01	12.264000000000001
1973-01-01	12.358200000000000
1974-01-01	13.004500000000000
1975-01-01	14.218300000000000
1976-01-01	15.225200000000000
1977-01-01	15.785900000000000
1978-01-01	15.785900000000000
1979-01-01	14.542000000000000
1980-01-01	12.126200000000000
1981-01-01	16.625500000000000
1982-01-01	21.424500000000000
1983-01-01	22.337900000000000
1984-01-01	22.337900000000000
1985-01-01	22.337900000000000
1986-01-01	22.337900000000000
1987-01-01	22.337900000000000
1988-01-01	22.337900000000000
1989-01-01	18.135400000000000
1990-01-01	19.683000000000000
1991-01-01	20.743200000000000
1992-01-01	20.846700000000000
1993-01-01	18.855999999999998
1994-01-01	15.478300000000000
1995-01-01	15.307100000000000
1996-01-01	13.683100000000000
1997-01-01	13.345200000000000
1998-01-01	16.020500000000000
1999-01-01	13.250800000000000
2000-01-01	11.753400000000000
2001-01-01	14.237000000000000
2002-01-01	13.027600000000000
2003-01-01	14.032400000000000
2004-01-01	12.551600000000000
2005-01-01	12.248500000000000
2006-01-01	13.600500000000000
2007-01-01	19.052600000000000
2008-01-01	18.537900000000000
2009-01-01	22.913700000000000
2010-01-01	19.865300000000000
2011-01-01	23.234400000000000
2012-01-01	28.992800000000000
2013-01-01	31.530100000000000
2014-01-01	33.315500000000000
2015-01-01	46.955200000000000