Year	Percent
1961-01-01	55.78970000000000
1962-01-01	61.71000000000000
1963-01-01	73.41490000000000
1964-01-01	82.48910000000000
1965-01-01	80.70650000000000
1966-01-01	70.66540000000000
1967-01-01	74.68030000000000
1968-01-01	84.99210000000000
1969-01-01	96.57450000000000
1970-01-01	105.09100000000001
1971-01-01	104.19100000000000
1972-01-01	98.73190000000000
1973-01-01	93.41150000000000
1974-01-01	99.32400000000000
1975-01-01	108.52799999999999
1976-01-01	92.98830000000000
1977-01-01	87.71770000000000
1978-01-01	93.74960000000000
1979-01-01	96.09200000000001
1980-01-01	92.03550000000000
1981-01-01	90.42850000000000
1982-01-01	81.02400000000000
1983-01-01	61.60740000000000
1984-01-01	60.54190000000000
1985-01-01	63.04010000000000
1986-01-01	58.00660000000000
1987-01-01	56.91150000000000
1988-01-01	52.70850000000000
1989-01-01	53.55270000000000
1990-01-01	53.55270000000000
1991-01-01	58.61970000000000
1992-01-01	57.67160000000000
1993-01-01	40.36570000000000
1994-01-01	38.63290000000000
1995-01-01	39.57540000000000
1996-01-01	27.20160000000000
1997-01-01	20.66060000000000
1998-01-01	72.97030000000000
1999-01-01	70.32040000000000
2000-01-01	51.39700000000000
2001-01-01	59.26760000000000
2002-01-01	64.25180000000000
2003-01-01	59.60930000000000
2004-01-01	55.21110000000000
2005-01-01	49.13130000000000
2006-01-01	47.53140000000000
2007-01-01	49.59420000000000
2008-01-01	49.14340000000000
2009-01-01	47.33670000000000
2010-01-01	50.92070000000000
2011-01-01	48.95940000000000
2012-01-01	54.94260000000000
2013-01-01	61.46860000000000