Year	Percent
1960-01-01	9.7067600000000010000
1961-01-01	11.2362000000000000000
1962-01-01	9.8982500000000000000
1963-01-01	13.8563000000000000000
1964-01-01	13.8563000000000000000
1965-01-01	13.8563000000000000000
1966-01-01	13.8563000000000000000
1967-01-01	13.8563000000000000000
1968-01-01	13.8563000000000000000
1969-01-01	17.1540000000000000000
1970-01-01	19.7890000000000000000
1971-01-01	23.1752000000000000000
1972-01-01	25.1063000000000000000
1973-01-01	20.0905000000000000000
1974-01-01	20.4832000000000000000
1975-01-01	21.6194000000000000000
1976-01-01	20.0539000000000000000
1977-01-01	17.3375000000000000000
1978-01-01	13.7472000000000000000
1979-01-01	9.7795500000000000000
1980-01-01	5.1269200000000000000
1981-01-01	1.3435300000000000000
1982-01-01	0.0021390000000000000
1983-01-01	0.0020370000000000000
1984-01-01	0.0009720000000000001
1985-01-01	0.0009720000000000001
1986-01-01	0.0009720000000000001
1987-01-01	0.0009720000000000001
1988-01-01	0.0009720000000000001
1989-01-01	16.8044000000000000000
1990-01-01	30.8894000000000000000
1991-01-01	30.4464000000000000000
1992-01-01	27.2842000000000000000
1993-01-01	23.9945000000000000000
1994-01-01	21.7318000000000000000
1995-01-01	22.3007000000000000000
1996-01-01	20.1919000000000000000
1997-01-01	15.0387000000000000000
1998-01-01	14.1517000000000000000
1999-01-01	12.1097000000000000000
2000-01-01	13.1915000000000000000
2001-01-01	13.5663000000000000000
2002-01-01	12.3698000000000000000
2003-01-01	12.4135000000000000000
2004-01-01	13.7794000000000000000
2005-01-01	13.3046000000000000000
2006-01-01	12.2762000000000000000
2007-01-01	11.9008000000000000000
2008-01-01	12.4432000000000000000
2009-01-01	12.4370000000000010000
2010-01-01	13.7966000000000000000
2011-01-01	14.1774000000000000000
2012-01-01	13.3078000000000000000
2013-01-01	11.9259999999999980000
2014-01-01	10.9529000000000000000
2015-01-01	12.0902000000000000000
2016-01-01	13.5719000000000000000