Year	Percent
1960-01-01	3.5786200000000000
1961-01-01	4.7682500000000000
1962-01-01	5.1698900000000005
1963-01-01	6.4541000000000000
1964-01-01	7.4892100000000010
1965-01-01	8.8684200000000000
1966-01-01	8.0455600000000000
1967-01-01	8.4602399999999990
1968-01-01	9.2286800000000000
1969-01-01	8.6232300000000000
1970-01-01	8.8392200000000000
1971-01-01	8.7201700000000000
1972-01-01	8.1610800000000000
1973-01-01	7.8525700000000000
1974-01-01	7.5308899999999990
1975-01-01	7.1291899999999995
1976-01-01	6.4245100000000000
1977-01-01	5.9909600000000000
1978-01-01	6.0772200000000000
1979-01-01	5.6131500000000000
1980-01-01	6.1286100000000000
1981-01-01	7.5895500000000000
1982-01-01	9.3048800000000000
1983-01-01	10.9518000000000000
1984-01-01	10.4269000000000000
1985-01-01	8.5356100000000000
1986-01-01	6.5898200000000000
1987-01-01	5.5862099999999995
1988-01-01	4.5162200000000000
1989-01-01	3.4900200000000000
1990-01-01	2.5494100000000000
1991-01-01	2.0393200000000000
1992-01-01	2.2520100000000000
1993-01-01	1.6493200000000001
1994-01-01	1.5720700000000000
1995-01-01	1.4133900000000000
1996-01-01	1.1017400000000000
1997-01-01	1.1556600000000001
1998-01-01	1.0832300000000000
1999-01-01	1.2203100000000000
2000-01-01	1.4507600000000000
2001-01-01	1.7857800000000000
2002-01-01	1.7851500000000000
2003-01-01	3.3877800000000002
2004-01-01	6.5457000000000000
2005-01-01	9.4360699999999990
2006-01-01	13.8677000000000000
2007-01-01	15.7436000000000000
2008-01-01	16.1310000000000000
2009-01-01	16.1120000000000020
2010-01-01	15.0181000000000000
2011-01-01	14.5843000000000000
2012-01-01	14.2806000000000000
2013-01-01	14.2773000000000000
2014-01-01	14.1281000000000000
2015-01-01	14.2736000000000000
2016-01-01	14.7174000000000000