Year	Percent
1978-01-01	0.3290770000000000
1979-01-01	0.8841250000000000
1980-01-01	0.9396220000000000
1981-01-01	0.9585000000000000
1982-01-01	0.9948130000000000
1983-01-01	1.1637500000000000
1984-01-01	1.2034200000000002
1985-01-01	3.5012199999999996
1986-01-01	3.1928200000000000
1987-01-01	3.0513200000000000
1988-01-01	2.7697100000000000
1989-01-01	2.4498000000000000
1990-01-01	1.6978500000000000
1991-01-01	1.1574300000000000
1992-01-01	1.3001000000000000
1993-01-01	3.5867800000000000
1994-01-01	4.9644300000000000
1995-01-01	5.1648600000000000
1996-01-01	7.4127800000000010
1997-01-01	10.0206000000000000
1998-01-01	13.3239000000000000
1999-01-01	11.0398000000000000
2000-01-01	10.2562000000000000
2001-01-01	8.5347300000000000
2002-01-01	7.6030800000000000
2003-01-01	6.0526400000000000
2004-01-01	5.3824400000000000
2005-01-01	5.5367000000000000
2006-01-01	5.0794000000000000
2007-01-01	3.5909000000000000
2008-01-01	3.0832300000000000
2009-01-01	2.7805200000000000
2010-01-01	2.7167600000000000
2011-01-01	2.7490500000000000
2012-01-01	4.1442800000000000
2013-01-01	4.3797200000000000
2014-01-01	5.1507700000000000
2015-01-01	4.8480300000000005
2016-01-01	4.9527500000000000