Year	Percent
1960-01-01	4.5579800000000010
1961-01-01	5.0375500000000000
1962-01-01	5.7773300000000000
1963-01-01	7.5218700000000000
1964-01-01	6.9918300000000000
1965-01-01	7.3994500000000000
1966-01-01	8.7485300000000000
1967-01-01	7.9138300000000000
1968-01-01	7.7653800000000000
1969-01-01	8.3802300000000010
1970-01-01	5.2754199999999996
1971-01-01	6.5674000000000000
1972-01-01	6.9899100000000010
1973-01-01	4.4005000000000000
1974-01-01	3.0421500000000000
1975-01-01	3.4839800000000003
1976-01-01	3.4279400000000000
1977-01-01	3.2857300000000005
1978-01-01	2.0161500000000000
1979-01-01	1.7132800000000000
1980-01-01	1.3145900000000000
1981-01-01	1.1106400000000000
1982-01-01	0.9473780000000000
1983-01-01	0.8661459999999999
1984-01-01	1.0545600000000000
1985-01-01	1.5213299999999998
1986-01-01	1.7547400000000002
1987-01-01	1.8521500000000000
1988-01-01	1.7686700000000000
1989-01-01	2.5248400000000000
1990-01-01	2.9284400000000000
1991-01-01	2.3056600000000000
1992-01-01	2.3720300000000000
1993-01-01	2.7054500000000000
1994-01-01	2.6985400000000000
1995-01-01	2.7728099999999998
1996-01-01	2.9285900000000002
1997-01-01	4.1328900000000000
1998-01-01	5.1026600000000000
1999-01-01	6.3088500000000000
2000-01-01	7.1627700000000000
2001-01-01	6.8723800000000010
2002-01-01	6.4874500000000000
2003-01-01	6.7031500000000000
2004-01-01	7.1236600000000010
2005-01-01	8.2910500000000000
2006-01-01	9.6820700000000000
2007-01-01	11.6386000000000000
2008-01-01	13.5645000000000000
2009-01-01	14.8090000000000010
2010-01-01	13.7782000000000000
2011-01-01	13.0947000000000000
2012-01-01	13.1988000000000000
2013-01-01	14.1439000000000000
2014-01-01	16.2200000000000000
2015-01-01	17.8538000000000000
2016-01-01	17.7598000000000000