Year	Percent
1963-01-01	0.17801700000000000
1964-01-01	0.14780700000000000
1965-01-01	0.14780700000000000
1966-01-01	0.22705900000000000
1967-01-01	0.54768500000000010
1968-01-01	0.34660799999999997
1969-01-01	0.04920100000000000
1970-01-01	0.04920100000000000
1971-01-01	0.15787900000000000
1972-01-01	0.61971300000000000
1973-01-01	0.45710900000000000
1974-01-01	0.00547100000000000
1975-01-01	0.00547100000000000
1976-01-01	0.39965000000000000
1977-01-01	0.38177100000000000
1978-01-01	0.16552200000000000
1979-01-01	1.10843000000000000
1980-01-01	3.05983000000000000
1981-01-01	5.80473000000000000
1982-01-01	8.64510000000000000
1983-01-01	11.14470000000000000
1984-01-01	11.12040000000000000
1985-01-01	10.54250000000000000
1986-01-01	10.44760000000000000
1987-01-01	10.24290000000000000
1988-01-01	9.50378999999999900
1989-01-01	8.46274000000000000
1990-01-01	8.39102000000000000
1991-01-01	8.38981000000000000
1992-01-01	8.35781000000000000
1993-01-01	8.25763999999999900
1994-01-01	8.16033000000000000
1995-01-01	7.74078000000000000
1996-01-01	6.67306000000000000
1997-01-01	6.58250000000000000
1998-01-01	7.02911000000000000
1999-01-01	7.77673000000000100
2000-01-01	7.54668000000000000
2001-01-01	6.37940000000000000
2002-01-01	5.74989000000000000
2003-01-01	5.29229000000000000
2004-01-01	4.60740000000000000
2005-01-01	3.85775000000000000
2006-01-01	3.20248000000000000
2007-01-01	2.76302000000000000
2008-01-01	2.51427000000000020
2009-01-01	3.42519000000000000
2010-01-01	4.22504000000000000
2011-01-01	4.97205000000000000
2012-01-01	5.13693000000000000
2013-01-01	5.02403000000000100
2014-01-01	4.76403000000000000
2015-01-01	4.66650000000000000
2016-01-01	4.82196000000000000