Year	Percent
1960-01-01	9.7878600000000000
1961-01-01	9.8233199999999990
1962-01-01	10.1924000000000000
1963-01-01	11.5483000000000000
1964-01-01	12.7636000000000000
1965-01-01	10.8168000000000000
1966-01-01	9.4150400000000000
1967-01-01	12.1931000000000000
1968-01-01	12.3490000000000000
1969-01-01	12.1340000000000000
1970-01-01	8.9291800000000000
1971-01-01	8.8847800000000010
1972-01-01	7.7142899999999990
1973-01-01	8.0872800000000000
1974-01-01	7.5286899999999990
1975-01-01	8.2272300000000000
1976-01-01	8.6622600000000000
1977-01-01	8.8355100000000010
1978-01-01	9.6587900000000000
1979-01-01	10.1657000000000000
1980-01-01	10.5595000000000000
1981-01-01	11.6624000000000000
1982-01-01	15.2875000000000000
1983-01-01	14.3368000000000000
1984-01-01	13.4755000000000000
1985-01-01	13.4990000000000000
1986-01-01	12.1193000000000000
1987-01-01	9.2017600000000000
1988-01-01	10.5786000000000000
1989-01-01	6.6408800000000000
1990-01-01	5.9540900000000000
1991-01-01	6.7243900000000000
1992-01-01	7.2542100000000005
1993-01-01	4.0381100000000000
1994-01-01	3.5812699999999995
1995-01-01	2.4382900000000003
1996-01-01	2.0931800000000000
1997-01-01	1.9494099999999999
1998-01-01	1.8362000000000000
1999-01-01	1.6858200000000000
2000-01-01	1.8403400000000000
2001-01-01	2.5357700000000000
2002-01-01	3.5934300000000000
2003-01-01	4.9690600000000000
2004-01-01	6.3746700000000000
2005-01-01	8.6680200000000000
2006-01-01	10.8148000000000000
2007-01-01	11.8502000000000000
2008-01-01	11.2443000000000000
2009-01-01	11.7278000000000000
2010-01-01	11.1209000000000000
2011-01-01	10.6058000000000000
2012-01-01	10.7565000000000000
2013-01-01	9.6322900000000000
2014-01-01	8.7085600000000000
2015-01-01	7.9533500000000000