Year	Percent
1960-01-01	3.8754199999999996
1961-01-01	3.9089400000000003
1962-01-01	4.2843800000000005
1963-01-01	4.9128300000000005
1964-01-01	5.1833200000000000
1965-01-01	5.8701700000000000
1966-01-01	5.8701700000000000
1967-01-01	5.8701700000000000
1968-01-01	5.8701700000000000
1969-01-01	10.6283000000000000
1970-01-01	12.9067000000000000
1971-01-01	12.6299000000000000
1972-01-01	11.6914000000000000
1973-01-01	12.8592000000000000
1974-01-01	17.7961000000000000
1975-01-01	19.9954000000000000
1976-01-01	20.2450000000000000
1977-01-01	21.7863000000000000
1978-01-01	22.7809000000000000
1979-01-01	23.9929000000000000
1980-01-01	21.3354000000000000
1981-01-01	22.2374000000000000
1982-01-01	25.3091000000000000
1983-01-01	27.5947000000000000
1984-01-01	33.7706000000000000
1985-01-01	34.7569000000000000
1986-01-01	32.1647000000000000
1987-01-01	33.0885000000000000
1988-01-01	27.6503000000000000
1989-01-01	27.7848000000000000
1990-01-01	27.6567000000000000
1991-01-01	25.7502000000000000
1992-01-01	24.3496000000000000
1993-01-01	26.5149000000000000
1994-01-01	20.0859000000000000
1995-01-01	16.9486000000000000
1996-01-01	15.5444000000000000
1997-01-01	14.1820000000000000
1998-01-01	15.4454000000000000
1999-01-01	13.9010000000000000
2000-01-01	15.2667000000000000
2001-01-01	16.3703000000000000
2002-01-01	16.2826000000000000
2003-01-01	19.9302000000000000
2004-01-01	21.4603000000000000
2005-01-01	22.7425000000000000
2006-01-01	23.4469000000000000
2007-01-01	24.7232000000000000
2008-01-01	26.5266000000000000
2009-01-01	28.8115000000000000
2010-01-01	30.7032000000000000
2011-01-01	32.3589000000000000
2012-01-01	33.9607000000000000
2013-01-01	35.9712000000000000
2014-01-01	37.9683000000000000
2015-01-01	40.5599000000000000
2016-01-01	42.7742000000000000