Year	Percent
1971-01-01	1.0868400000000000
1972-01-01	2.0694700000000000
1973-01-01	2.2939900000000000
1974-01-01	2.1599500000000000
1975-01-01	3.0381800000000000
1976-01-01	3.5271400000000000
1977-01-01	3.7564800000000003
1978-01-01	4.4289800000000000
1979-01-01	3.9863100000000000
1980-01-01	2.3811800000000000
1981-01-01	2.0317000000000000
1982-01-01	2.1935500000000000
1983-01-01	2.3280500000000000
1984-01-01	2.8311200000000000
1985-01-01	4.5558000000000000
1986-01-01	4.2797300000000010
1987-01-01	3.4939300000000000
1988-01-01	2.5327200000000000
1989-01-01	2.1093400000000000
1990-01-01	1.5932000000000000
1991-01-01	1.1327700000000000
1992-01-01	1.1483100000000000
1993-01-01	0.8502730000000000
1994-01-01	1.7860200000000002
1995-01-01	2.3858200000000003
1996-01-01	2.9530900000000000
1997-01-01	3.1549400000000003
1998-01-01	4.3687400000000000
1999-01-01	5.3669699999999990
2000-01-01	6.2077500000000000
2001-01-01	8.0805400000000000
2002-01-01	11.3462000000000000
2003-01-01	11.4346000000000000
2004-01-01	10.8842000000000000
2005-01-01	10.3368000000000000
2006-01-01	12.1533000000000000
2007-01-01	14.1329000000000000
2008-01-01	12.4194000000000000
2009-01-01	12.8913000000000000
2010-01-01	11.8282000000000000
2011-01-01	11.9219000000000000
2012-01-01	13.6792000000000000
2013-01-01	15.7269000000000000
2014-01-01	15.7465000000000000
2015-01-01	18.8775000000000000
2016-01-01	21.1023000000000000