Year	Percent
1973-01-01	10.9717000000000000
1974-01-01	10.5820000000000000
1975-01-01	11.2897000000000000
1976-01-01	11.4946000000000000
1977-01-01	12.0775000000000000
1978-01-01	13.4652000000000000
1979-01-01	13.8947000000000000
1980-01-01	14.0327000000000000
1981-01-01	15.6529000000000000
1982-01-01	21.2110000000000000
1983-01-01	17.8496000000000000
1984-01-01	14.3432000000000000
1985-01-01	14.2652000000000000
1986-01-01	12.6948000000000000
1987-01-01	9.4658000000000000
1988-01-01	10.7358000000000000
1989-01-01	6.8210600000000010
1990-01-01	6.1161100000000000
1991-01-01	6.7289400000000000
1992-01-01	9.3297400000000000
1993-01-01	6.0234600000000000
1994-01-01	4.3648300000000000
1995-01-01	2.7826299999999997
1996-01-01	2.2724100000000000
1997-01-01	2.0557700000000000
1998-01-01	1.9372400000000000
1999-01-01	1.8301500000000000
2000-01-01	2.0770500000000000
2001-01-01	2.9279100000000000
2002-01-01	4.2433800000000000
2003-01-01	5.8537500000000000
2004-01-01	7.3680400000000000
2005-01-01	10.0181000000000000
2006-01-01	12.9075000000000000
2007-01-01	14.2582000000000000
2008-01-01	13.8781000000000000
2009-01-01	15.5116000000000000
2010-01-01	15.4621000000000000
2011-01-01	15.3144000000000000
2012-01-01	15.3942000000000000
2013-01-01	13.2316000000000000
2014-01-01	12.1500000000000000
2015-01-01	11.7280000000000000