Year	Percent
1964-01-01	2.4466900000000003
1965-01-01	2.4724800000000000
1966-01-01	2.9051000000000000
1967-01-01	3.6234900000000003
1968-01-01	4.7532500000000000
1969-01-01	5.3258300000000010
1970-01-01	4.3413200000000000
1971-01-01	4.1302400000000010
1972-01-01	4.2282900000000000
1973-01-01	4.4246800000000000
1974-01-01	4.3778600000000000
1975-01-01	3.2527700000000000
1976-01-01	3.0935099999999998
1977-01-01	3.5297600000000000
1978-01-01	4.3220300000000010
1979-01-01	5.9438800000000000
1980-01-01	7.2233600000000004
1981-01-01	9.3748899999999990
1982-01-01	9.9856300000000000
1983-01-01	11.3572000000000000
1984-01-01	11.8811000000000000
1985-01-01	11.3560000000000000
1986-01-01	12.2720000000000000
1987-01-01	12.3053000000000000
1988-01-01	11.3359999999999990
1989-01-01	9.4069800000000000
1990-01-01	8.1718800000000000
1991-01-01	6.9626100000000010
1992-01-01	5.6426500000000000
1993-01-01	4.8461200000000000
1994-01-01	4.0390500000000000
1995-01-01	4.3238699999999990
1996-01-01	5.0440700000000000
1997-01-01	5.2087000000000000
1998-01-01	6.3964600000000000
1999-01-01	6.8729500000000000
2000-01-01	8.2367700000000000
2001-01-01	9.1422600000000000
2002-01-01	9.3670000000000000
2003-01-01	10.7753000000000000
2004-01-01	11.4441000000000000
2005-01-01	12.3969000000000000
2006-01-01	14.2007000000000000
2007-01-01	13.4016000000000000
2008-01-01	9.7147000000000000
2009-01-01	9.6530600000000000
2010-01-01	10.3107000000000000
2011-01-01	10.4195000000000000
2012-01-01	11.5974000000000000
2013-01-01	10.6212000000000000
2014-01-01	9.6281000000000000
2015-01-01	11.8791000000000000
2016-01-01	13.4728000000000000