Year	Percent
1964-01-01	2.6691200000000000
1965-01-01	2.6572900000000000
1966-01-01	2.4739500000000000
1967-01-01	2.6499900000000003
1968-01-01	3.0820600000000000
1969-01-01	2.6823200000000003
1970-01-01	2.5458200000000000
1971-01-01	3.7868699999999995
1972-01-01	4.5232199999999990
1973-01-01	4.4267100000000000
1974-01-01	6.4432199999999990
1975-01-01	5.3352400000000000
1976-01-01	3.0519300000000000
1977-01-01	3.0231800000000000
1978-01-01	4.1031900000000010
1979-01-01	6.0566200000000000
1980-01-01	6.1298200000000000
1981-01-01	8.1742700000000000
1982-01-01	8.5631200000000000
1983-01-01	7.1933100000000000
1984-01-01	5.0442599999999995
1985-01-01	3.2521100000000000
1986-01-01	3.8371600000000000
1987-01-01	4.2590800000000000
1988-01-01	4.8987000000000000
1989-01-01	6.0755300000000005
1990-01-01	7.3735600000000000
1991-01-01	9.1500700000000000
1992-01-01	10.0671000000000000
1993-01-01	12.0655000000000000
1994-01-01	14.0643000000000000
1995-01-01	13.1516000000000000
1996-01-01	12.5455000000000000
1997-01-01	11.1535000000000000
1998-01-01	11.6769000000000000
1999-01-01	11.8775000000000000
2000-01-01	14.0870000000000000
2001-01-01	15.6932000000000000
2002-01-01	17.2061000000000000
2003-01-01	19.1853000000000000
2004-01-01	16.6237000000000000
2005-01-01	14.9093000000000000
2006-01-01	14.6652000000000000
2007-01-01	14.2806000000000000
2008-01-01	12.8694000000000000
2009-01-01	13.0551000000000000
2010-01-01	15.3729000000000000
2011-01-01	18.6062000000000000
2012-01-01	19.7086000000000000
2013-01-01	17.8603000000000000
2014-01-01	16.8146000000000000
2015-01-01	16.7779000000000000
2016-01-01	15.1242000000000000