Year	Percent
1976-01-01	0.7980800000000000
1977-01-01	3.8397699999999997
1978-01-01	4.9934800000000000
1979-01-01	4.0284100000000000
1980-01-01	8.2178200000000000
1981-01-01	15.3234000000000000
1982-01-01	20.7007000000000000
1983-01-01	25.1593000000000000
1984-01-01	27.7763000000000000
1985-01-01	27.6711000000000000
1986-01-01	24.2209000000000000
1987-01-01	20.2957000000000000
1988-01-01	17.6585000000000000
1989-01-01	18.0699000000000000
1990-01-01	18.2587000000000000
1991-01-01	15.4992000000000000
1992-01-01	12.9768000000000000
1993-01-01	13.1914000000000000
1994-01-01	13.8225000000000000
1995-01-01	13.3183000000000000
1996-01-01	13.5434000000000000
1997-01-01	12.7963000000000000
1998-01-01	15.4130000000000000
1999-01-01	16.3523000000000000
2000-01-01	16.3616000000000000
2001-01-01	18.3265000000000000
2002-01-01	20.4054000000000000
2003-01-01	17.3833000000000000
2004-01-01	24.0084000000000000
2005-01-01	32.8702000000000000
2006-01-01	37.1392000000000000
2007-01-01	47.4842000000000000
2008-01-01	56.7075000000000000
2009-01-01	64.7122000000000000
2010-01-01	63.0506000000000000
2011-01-01	54.6560000000000060
2012-01-01	49.5077000000000000
2013-01-01	40.9374000000000000
2014-01-01	37.8000000000000000
2015-01-01	39.1997000000000000
2016-01-01	42.6667000000000000