Year	Percent
1966-01-01	0.2558100000000000
1967-01-01	0.2516180000000000
1968-01-01	0.2895420000000000
1969-01-01	0.2603450000000000
1970-01-01	0.2603450000000000
1971-01-01	0.1895780000000000
1972-01-01	0.8257270000000000
1973-01-01	0.6951890000000001
1974-01-01	1.5780800000000000
1975-01-01	4.9214800000000000
1976-01-01	7.9898100000000000
1977-01-01	11.6205000000000000
1978-01-01	15.6499000000000000
1979-01-01	16.1262000000000000
1980-01-01	13.8091000000000000
1981-01-01	14.3421000000000000
1982-01-01	18.3574000000000000
1983-01-01	17.3848000000000000
1984-01-01	21.9151000000000000
1985-01-01	27.5847000000000000
1986-01-01	35.2456000000000000
1987-01-01	41.8499000000000000
1988-01-01	36.2381000000000000
1989-01-01	33.8933000000000000
1990-01-01	36.4869000000000000
1991-01-01	34.9348000000000000
1992-01-01	28.6944000000000000
1993-01-01	21.8599000000000000
1994-01-01	18.7579000000000000
1995-01-01	14.8000000000000000
1996-01-01	12.6303000000000000
1997-01-01	13.4575000000000000
1998-01-01	15.5494000000000000
1999-01-01	14.0466000000000000
2000-01-01	15.8979000000000000
2001-01-01	16.0657000000000000
2002-01-01	14.0346000000000000
2003-01-01	10.9177000000000000
2004-01-01	10.9763000000000000
2005-01-01	6.6039400000000000
2006-01-01	6.3463800000000000
2007-01-01	7.3087600000000000
2008-01-01	5.7593200000000000
2009-01-01	8.1780200000000000
2010-01-01	9.8027699999999990
2011-01-01	11.8312000000000000
2012-01-01	13.4812000000000000
2013-01-01	12.4805000000000000
2014-01-01	10.0245000000000000
2015-01-01	11.5200000000000000
2016-01-01	8.0337100000000010