Year	Percent
1960-01-01	35.08580000000000
1961-01-01	34.12030000000000
1962-01-01	36.50800000000000
1963-01-01	36.08690000000000
1964-01-01	36.07530000000000
1965-01-01	36.18370000000000
1966-01-01	37.58140000000000
1967-01-01	38.04090000000000
1968-01-01	37.34980000000000
1969-01-01	36.09090000000000
1970-01-01	37.33890000000000
1971-01-01	39.63900000000000
1972-01-01	38.69340000000000
1973-01-01	38.07720000000000
1974-01-01	38.05420000000000
1975-01-01	40.45180000000000
1976-01-01	40.91570000000000
1977-01-01	41.86950000000000
1978-01-01	41.92510000000000
1979-01-01	41.04720000000000
1980-01-01	41.94610000000000
1981-01-01	43.19340000000000
1982-01-01	45.24340000000000
1983-01-01	47.92540000000000
1984-01-01	50.12440000000000
1985-01-01	54.37500000000000
1986-01-01	58.40220000000000
1987-01-01	62.85420000000000
1988-01-01	68.11910000000000
1989-01-01	73.91250000000000
1990-01-01	79.56230000000000
1991-01-01	89.46040000000000
1992-01-01	90.19460000000000
1993-01-01	82.66840000000000
1994-01-01	70.60120000000000
1995-01-01	60.80620000000000
1996-01-01	57.76840000000000
1997-01-01	52.15310000000000
1998-01-01	48.75540000000000
1999-01-01	51.21220000000000
2000-01-01	51.37640000000000
2001-01-01	52.55010000000000
2002-01-01	53.65680000000000
2003-01-01	57.47260000000000
2004-01-01	60.75410000000000
2005-01-01	65.50510000000000
2006-01-01	69.93980000000000
2007-01-01	72.45430000000000
2008-01-01	78.00340000000000
2009-01-01	86.20120000000000
2010-01-01	86.04970000000000
2011-01-01	87.34560000000000
2012-01-01	91.00170000000000
2013-01-01	92.17200000000001
2014-01-01	93.09770000000000
2015-01-01	93.30180000000000
2016-01-01	93.41630000000000