Year	Percent
1960-01-01	4.7434100000000000
1961-01-01	4.9247800000000000
1962-01-01	5.2119000000000000
1963-01-01	7.1455800000000010
1964-01-01	8.0895000000000000
1965-01-01	7.4188700000000000
1966-01-01	8.0410700000000000
1967-01-01	10.0507000000000000
1968-01-01	9.2095500000000000
1969-01-01	9.2456800000000000
1970-01-01	7.7298700000000000
1971-01-01	8.2949000000000000
1972-01-01	7.8787899999999995
1973-01-01	8.9058800000000000
1974-01-01	8.8835600000000010
1975-01-01	8.9120500000000000
1976-01-01	8.3782800000000000
1977-01-01	9.8525100000000000
1978-01-01	11.9598000000000000
1979-01-01	12.2681000000000000
1980-01-01	12.7526000000000000
1981-01-01	14.1618000000000000
1982-01-01	18.2789000000000000
1983-01-01	18.4267000000000000
1984-01-01	18.5781000000000000
1985-01-01	22.4884000000000000
1986-01-01	22.3854000000000000
1987-01-01	15.5651000000000000
1988-01-01	17.6662000000000000
1989-01-01	12.5118000000000000
1990-01-01	12.8498000000000000
1991-01-01	13.6795000000000000
1992-01-01	17.6452000000000000
1993-01-01	13.2254000000000000
1994-01-01	11.2482000000000000
1995-01-01	6.9778400000000000
1996-01-01	5.4025500000000000
1997-01-01	4.4135599999999995
1998-01-01	4.7311200000000000
1999-01-01	4.9805300000000000
2000-01-01	5.3320500000000000
2001-01-01	6.7290700000000000
2002-01-01	8.0771600000000010
2003-01-01	8.9761899999999990
2004-01-01	10.0402000000000000
2005-01-01	12.6331000000000000
2006-01-01	13.8512000000000000
2007-01-01	13.8738000000000000
2008-01-01	13.4835000000000000
2009-01-01	14.7505000000000000
2010-01-01	14.7891000000000000
2011-01-01	14.8095000000000000
2012-01-01	15.4273000000000000
2013-01-01	13.4302000000000000
2014-01-01	12.1754000000000000
2015-01-01	11.9172000000000000