Year	Percent
1960-01-01	0.627019000000000000000
1961-01-01	0.791764000000000000000
1962-01-01	1.011950000000000000000
1963-01-01	1.348570000000000000000
1964-01-01	2.196900000000000000000
1965-01-01	2.734950000000000000000
1966-01-01	3.420069999999999500000
1967-01-01	4.585260000000000000000
1968-01-01	5.492780000000001000000
1969-01-01	5.370630000000000000000
1970-01-01	4.816020000000000000000
1971-01-01	4.734180000000000000000
1972-01-01	4.662170000000000000000
1973-01-01	4.101000000000000000000
1974-01-01	3.726320000000000000000
1975-01-01	4.013630000000000000000
1976-01-01	4.708990000000000000000
1977-01-01	5.498320000000000000000
1978-01-01	8.920600000000000000000
1979-01-01	12.939800000000000000000
1980-01-01	15.284400000000000000000
1981-01-01	17.278100000000000000000
1982-01-01	15.703000000000000000000
1983-01-01	16.503000000000000000000
1984-01-01	19.184600000000000000000
1985-01-01	17.406300000000000000000
1986-01-01	16.697400000000000000000
1987-01-01	17.156300000000000000000
1988-01-01	15.115100000000000000000
1989-01-01	13.460100000000000000000
1990-01-01	12.202500000000000000000
1991-01-01	8.613450000000000000000
1992-01-01	7.009970000000000000000
1993-01-01	5.826350000000000000000
1994-01-01	5.318169999999999000000
1995-01-01	5.299370000000000000000
1996-01-01	8.774770000000000000000
1997-01-01	11.532900000000000000000
1998-01-01	11.140300000000000000000
1999-01-01	9.076030000000001000000
2000-01-01	6.086500000000000000000
2001-01-01	3.386910000000000000000
2002-01-01	1.783720000000000000000
2003-01-01	1.588790000000000000000
2004-01-01	1.449910000000000000000
2005-01-01	1.345950000000000000000
2006-01-01	1.150900000000000000000
2007-01-01	0.869412999999999900000
2008-01-01	0.642984000000000000000
2009-01-01	0.517813000000000000000
2010-01-01	0.410427999999999960000
2011-01-01	0.323480000000000050000
2012-01-01	0.243058000000000000000
2013-01-01	0.175252000000000000000
2014-01-01	0.104606999999999990000
2015-01-01	0.034492000000000000000
2016-01-01	0.000026000000000000002