Year	Percent
1960-01-01	1.4696500000000000
1961-01-01	2.6532800000000000
1962-01-01	2.7766800000000000
1963-01-01	3.0133099999999997
1964-01-01	1.6543299999999999
1965-01-01	1.5561900000000000
1966-01-01	1.6505500000000000
1967-01-01	1.8796700000000002
1968-01-01	4.2863200000000000
1969-01-01	2.2853600000000000
1970-01-01	4.0931000000000000
1971-01-01	3.9562500000000000
1972-01-01	3.3968400000000000
1973-01-01	3.2613800000000000
1974-01-01	4.1816600000000000
1975-01-01	3.9128199999999995
1976-01-01	4.1770500000000000
1977-01-01	4.7931700000000000
1978-01-01	5.7063700000000000
1979-01-01	7.1371899999999995
1980-01-01	6.3173400000000000
1981-01-01	4.2449800000000000
1982-01-01	3.8182800000000000
1983-01-01	3.8182800000000000
1984-01-01	5.2546400000000000
1985-01-01	5.6003700000000000
1986-01-01	5.9404300000000000
1987-01-01	6.6215600000000010
1988-01-01	6.0281000000000000
1989-01-01	5.5516100000000000
1990-01-01	5.2006600000000000
1991-01-01	4.7080300000000000
1992-01-01	4.3053000000000000
1993-01-01	3.1870800000000000
1994-01-01	2.4613600000000000
1995-01-01	3.0866900000000000
1996-01-01	3.1501300000000000
1997-01-01	3.0961300000000000
1998-01-01	2.9070900000000000
1999-01-01	2.9467500000000000
2000-01-01	3.1789900000000000
2001-01-01	3.3817100000000000
2002-01-01	4.0324700000000000
2003-01-01	4.0017300000000000
2004-01-01	2.8524300000000000
2005-01-01	2.6000600000000000
2006-01-01	3.6419900000000003
2007-01-01	3.8255000000000000
2008-01-01	3.7914600000000000
2009-01-01	4.5526400000000000
2010-01-01	4.4622400000000000
2011-01-01	4.8038900000000000
2012-01-01	5.5925400000000005
2013-01-01	6.0969600000000000
2014-01-01	6.7496300000000010
2015-01-01	8.4709899999999990