Year	Percent
1960-01-01	57.7167000000000000
1961-01-01	60.9375000000000000
1962-01-01	70.7155000000000000
1963-01-01	79.7738000000000000
1964-01-01	79.4281000000000000
1965-01-01	76.4508000000000000
1966-01-01	72.2647000000000000
1967-01-01	71.0877000000000000
1968-01-01	81.1113000000000000
1969-01-01	92.0266000000000000
1970-01-01	86.1550000000000000
1971-01-01	78.3680000000000000
1972-01-01	78.9680000000000000
1973-01-01	77.1105000000000000
1974-01-01	73.1318000000000000
1975-01-01	63.7510000000000050
1976-01-01	56.5330000000000000
1977-01-01	55.7713000000000000
1978-01-01	52.3594000000000000
1979-01-01	42.2632000000000000
1980-01-01	33.6803000000000000
1981-01-01	28.3589000000000000
1982-01-01	24.4026000000000000
1983-01-01	24.7230000000000030
1984-01-01	24.5388000000000000
1985-01-01	21.9914000000000000
1986-01-01	23.4247000000000000
1987-01-01	24.5204000000000000
1988-01-01	26.1513000000000000
1989-01-01	29.7650000000000000
1990-01-01	17.1391000000000000
1991-01-01	17.6189000000000000
1992-01-01	25.9728000000000000
1993-01-01	39.6833000000000000
1994-01-01	9.2919500000000000
1995-01-01	6.0971400000000004
1996-01-01	7.7363000000000000
1997-01-01	7.7063900000000000
1998-01-01	9.7978100000000000
1999-01-01	14.1029000000000000
2000-01-01	14.4480000000000000
2001-01-01	15.3656000000000000
2002-01-01	19.3784000000000000
2003-01-01	22.8046000000000000
2004-01-01	27.7397000000000000
2005-01-01	37.8789000000000000
2006-01-01	39.3712000000000000
2007-01-01	53.5934000000000000
2008-01-01	78.7740000000000000
2009-01-01	78.5074000000000000
2010-01-01	72.3586000000000000
2011-01-01	75.4188000000000000
2012-01-01	86.5258000000000000
2013-01-01	85.7516000000000000
2014-01-01	77.2641000000000000
2015-01-01	74.1837000000000000
2016-01-01	70.0286000000000000