Year	Percent
1960-01-01	21.23590000000000
1961-01-01	19.30930000000000
1962-01-01	19.85030000000000
1963-01-01	25.87120000000000
1964-01-01	26.87710000000000
1965-01-01	26.93990000000000
1966-01-01	26.75130000000000
1967-01-01	27.65790000000000
1968-01-01	29.20160000000000
1969-01-01	30.16550000000000
1970-01-01	29.54960000000000
1971-01-01	31.74370000000000
1972-01-01	36.43250000000000
1973-01-01	39.62330000000000
1974-01-01	37.23750000000000
1975-01-01	40.56020000000000
1976-01-01	44.07730000000000
1977-01-01	50.32160000000000
1978-01-01	52.17620000000000
1979-01-01	54.46820000000000
1980-01-01	56.07190000000000
1981-01-01	61.33800000000000
1982-01-01	81.42930000000000
1983-01-01	98.25350000000000
1984-01-01	98.86140000000000
1985-01-01	101.44200000000001
1986-01-01	109.53800000000000
1987-01-01	69.54620000000000
1988-01-01	73.85210000000000
1989-01-01	38.85150000000000
1990-01-01	38.66190000000000
1991-01-01	26.22510000000000
1992-01-01	35.66250000000000
1993-01-01	42.88970000000000
1994-01-01	35.52180000000000
1995-01-01	36.58120000000000
1996-01-01	40.39680000000000
1997-01-01	43.00660000000000
1998-01-01	46.75320000000000
1999-01-01	44.52560000000000
2000-01-01	46.42120000000000
2001-01-01	50.10260000000000
2002-01-01	53.76690000000000
2003-01-01	55.95340000000000
2004-01-01	56.32990000000000
2005-01-01	57.70240000000000
2006-01-01	58.88660000000000
2007-01-01	57.98070000000000
2008-01-01	57.58060000000000
2009-01-01	55.37070000000000
2010-01-01	51.22340000000000
2011-01-01	51.20470000000000
2012-01-01	51.64080000000000
2013-01-01	53.80230000000000
2014-01-01	53.80590000000000
2015-01-01	52.79480000000000
2016-01-01	51.23140000000000