Year	Percent
1960-01-01	13.6842000000000000
1961-01-01	12.5403000000000000
1962-01-01	12.2549000000000000
1963-01-01	12.2156000000000000
1964-01-01	11.0220000000000000
1965-01-01	9.7839500000000000
1966-01-01	8.8191899999999990
1967-01-01	8.9982899999999990
1968-01-01	9.7588400000000000
1969-01-01	9.4782300000000000
1970-01-01	7.2067600000000010
1971-01-01	7.4360800000000005
1972-01-01	6.5286100000000000
1973-01-01	6.2686600000000000
1974-01-01	6.8559199999999990
1975-01-01	7.4647100000000000
1976-01-01	8.0945400000000000
1977-01-01	8.5686300000000000
1978-01-01	8.5686300000000000
1979-01-01	8.3632200000000000
1980-01-01	7.3283000000000000
1981-01-01	10.7785000000000000
1982-01-01	13.7176000000000000
1983-01-01	13.7451000000000000
1984-01-01	13.7451000000000000
1985-01-01	13.7451000000000000
1986-01-01	13.7451000000000000
1987-01-01	13.7451000000000000
1988-01-01	13.7451000000000000
1989-01-01	11.5304000000000000
1990-01-01	12.0262000000000000
1991-01-01	12.9234000000000000
1992-01-01	13.4348000000000000
1993-01-01	11.4819000000000000
1994-01-01	8.5342300000000000
1995-01-01	7.6507200000000000
1996-01-01	6.5864600000000010
1997-01-01	6.7719000000000000
1998-01-01	8.6762199999999990
1999-01-01	7.0045399999999995
2000-01-01	6.4852300000000005
2001-01-01	7.2046500000000000
2002-01-01	5.9688500000000000
2003-01-01	7.0434500000000000
2004-01-01	6.1883000000000000
2005-01-01	6.0017900000000000
2006-01-01	6.9662500000000000
2007-01-01	10.8759000000000000
2008-01-01	11.0131000000000000
2009-01-01	13.6379000000000000
2010-01-01	12.5165000000000000
2011-01-01	15.9962000000000000
2012-01-01	21.0702000000000000
2013-01-01	22.8785000000000000
2014-01-01	24.1694000000000000
2015-01-01	34.0809000000000000