Year	Percent
1961-01-01	78.15600000000000
1962-01-01	55.15070000000000
1963-01-01	61.45190000000000
1964-01-01	56.60840000000000
1965-01-01	49.33560000000000
1966-01-01	47.25140000000000
1967-01-01	45.46810000000000
1968-01-01	46.48830000000000
1969-01-01	48.26570000000000
1970-01-01	47.75360000000000
1971-01-01	37.92410000000000
1972-01-01	30.07770000000000
1973-01-01	21.47450000000000
1974-01-01	17.92600000000000
1975-01-01	18.78730000000000
1976-01-01	22.31880000000000
1977-01-01	34.06240000000000
1978-01-01	43.80710000000000
1979-01-01	53.59120000000000
1980-01-01	66.70630000000000
1981-01-01	79.06600000000000
1982-01-01	81.92700000000000
1983-01-01	76.39000000000000
1984-01-01	69.38310000000000
1985-01-01	59.65410000000000
1986-01-01	52.22500000000000
1987-01-01	50.85320000000000
1988-01-01	50.69170000000000
1989-01-01	55.95040000000000
1990-01-01	61.59140000000000
1991-01-01	62.11010000000000
1992-01-01	65.22080000000000
1993-01-01	68.98220000000000
1994-01-01	72.60830000000000
1995-01-01	76.31070000000000
1996-01-01	79.31760000000000
1997-01-01	80.60940000000000
1998-01-01	81.33010000000000
1999-01-01	82.08600000000000
2000-01-01	82.49410000000000
2001-01-01	82.99020000000000
2002-01-01	83.61000000000000
2003-01-01	85.53770000000000
2004-01-01	88.57480000000000
2005-01-01	91.79480000000000
2006-01-01	94.62700000000001
2007-01-01	96.53480000000000
2008-01-01	97.44610000000000
2009-01-01	97.52300000000000
2010-01-01	97.49380000000000
2011-01-01	97.73530000000000
2012-01-01	97.99840000000000
2013-01-01	98.21650000000000
2014-01-01	98.82770000000000
2015-01-01	99.37030000000000
2016-01-01	99.48290000000000