Year	Percent
1960-01-01	9.1000000000000000
1961-01-01	9.5000000000000000
1962-01-01	11.1000000000000000
1963-01-01	7.2000000000000000
1964-01-01	6.8000000000000000
1965-01-01	6.7750000000000000
1966-01-01	7.1100000000000000
1967-01-01	7.4250000000000000
1968-01-01	7.2357100000000010
1969-01-01	6.7125000000000000
1970-01-01	4.4938400000000005
1971-01-01	3.8938500000000000
1972-01-01	3.5555700000000000
1973-01-01	4.1956800000000000
1974-01-01	5.9998400000000000
1975-01-01	5.4292200000000000
1976-01-01	3.0972700000000000
1977-01-01	3.0647100000000000
1978-01-01	2.8699400000000000
1979-01-01	1.7797500000000000
1980-01-01	2.0364200000000000
1981-01-01	3.7791900000000003
1982-01-01	4.0597800000000000
1983-01-01	7.6266899999999990
1984-01-01	5.8827000000000000
1985-01-01	6.9501300000000010
1986-01-01	9.0663900000000000
1987-01-01	11.9837000000000000
1988-01-01	9.3261899999999990
1989-01-01	7.0005399999999990
1990-01-01	3.8876000000000000
1991-01-01	4.1341100000000000
1992-01-01	4.1012699999999995
1993-01-01	4.0379900000000000
1994-01-01	3.5451500000000000
1995-01-01	3.0098100000000000
1996-01-01	2.8331000000000000
1997-01-01	2.5335200000000000
1998-01-01	2.3188600000000000
1999-01-01	2.1971700000000003
2000-01-01	2.2396200000000000
2001-01-01	4.7925000000000000
2002-01-01	11.5012000000000000
2003-01-01	14.7040000000000000
2004-01-01	13.2053000000000000
2005-01-01	10.3920000000000010
2006-01-01	7.7211300000000005
2007-01-01	6.3115100000000000
2008-01-01	5.5753200000000000
2009-01-01	6.7009200000000000
2010-01-01	7.1807500000000000
2011-01-01	7.9723000000000000
2012-01-01	10.1857000000000000
2013-01-01	12.4145000000000000
2014-01-01	13.5590000000000010
2015-01-01	16.6608000000000000
2016-01-01	16.6734000000000000