Year	Percent
1960-01-01	3.77722000000000000
1961-01-01	3.94344000000000030
1962-01-01	3.98481000000000000
1963-01-01	6.04353000000000050
1964-01-01	8.11965000000000000
1965-01-01	8.04356999999999900
1966-01-01	7.96470000000000000
1967-01-01	10.03990000000000000
1968-01-01	10.97620000000000000
1969-01-01	9.87215000000000000
1970-01-01	9.82538000000000100
1971-01-01	9.18843000000000000
1972-01-01	8.79958000000000000
1973-01-01	7.95017000000000000
1974-01-01	5.98029000000000000
1975-01-01	4.72690000000000000
1976-01-01	4.07803000000000000
1977-01-01	3.24079000000000000
1978-01-01	2.79024000000000030
1979-01-01	2.38000000000000000
1980-01-01	2.24519000000000000
1981-01-01	2.18614000000000000
1982-01-01	2.08815000000000000
1983-01-01	3.06872000000000000
1984-01-01	3.83791000000000000
1985-01-01	3.99296000000000000
1986-01-01	4.27387000000000000
1987-01-01	4.20418000000000000
1988-01-01	4.12246000000000000
1989-01-01	4.85088000000000000
1990-01-01	5.63531000000000000
1991-01-01	3.60721000000000000
1992-01-01	5.96729000000000000
1993-01-01	8.94275000000000000
1994-01-01	8.43510000000000000
1995-01-01	7.36136000000000000
1996-01-01	6.78879000000000000
1997-01-01	8.43578999999999900
1998-01-01	8.32516000000000000
1999-01-01	7.22138999999999950
2000-01-01	7.43143000000000100
2001-01-01	7.35170000000000000
2002-01-01	8.31876000000000100
2003-01-01	7.32666000000000000
2004-01-01	5.56107000000000000
2005-01-01	5.33785000000000000
2006-01-01	4.60616000000000000
2007-01-01	3.79468000000000050
2008-01-01	3.48930000000000000
2009-01-01	3.56030000000000000
2010-01-01	2.97947000000000000
2011-01-01	2.82681000000000000
2012-01-01	3.21597000000000000
2013-01-01	1.70114000000000000
2014-01-01	0.15353499999999998
2015-01-01	0.14149900000000000
2016-01-01	0.13301400000000002