Year	Percent
1960-01-01	39.91980000000000
1961-01-01	42.12290000000000
1962-01-01	43.34410000000000
1963-01-01	43.05350000000000
1964-01-01	42.67470000000000
1965-01-01	46.34020000000000
1966-01-01	47.48730000000000
1967-01-01	49.12990000000000
1968-01-01	45.08550000000000
1969-01-01	42.20300000000000
1970-01-01	40.90290000000000
1971-01-01	44.59260000000000
1972-01-01	42.20570000000000
1973-01-01	41.13010000000000
1974-01-01	44.11150000000000
1975-01-01	58.74070000000000
1976-01-01	58.99980000000000
1977-01-01	52.08560000000000
1978-01-01	56.82830000000000
1979-01-01	75.59810000000000
1980-01-01	81.24280000000000
1981-01-01	88.17399999999999
1982-01-01	88.38850000000000
1983-01-01	85.15940000000000
1984-01-01	80.03290000000000
1985-01-01	79.18180000000000
1986-01-01	78.01810000000000
1987-01-01	83.78820000000000
1988-01-01	84.14350000000000
1989-01-01	85.25870000000000
1990-01-01	92.34970000000000
1991-01-01	94.13560000000000
1992-01-01	102.19100000000000
1993-01-01	102.19100000000000
1994-01-01	79.02160000000000
1995-01-01	79.86180000000000
1996-01-01	79.99550000000000
1997-01-01	82.78299999999999
1998-01-01	82.78299999999999
1999-01-01	82.78299999999999
2000-01-01	95.93870000000000
2001-01-01	78.13020000000000
2002-01-01	71.06440000000000
2003-01-01	66.77650000000000
2004-01-01	65.77160000000000
2005-01-01	67.02800000000000
2006-01-01	69.98470000000000
2007-01-01	77.39740000000000
2008-01-01	96.22750000000000
2009-01-01	108.15500000000000
2010-01-01	94.64800000000000
2011-01-01	85.94380000000000
2012-01-01	86.71620000000000
2013-01-01	87.73520000000000
2014-01-01	87.71400000000000
2015-01-01	91.23670000000000
2016-01-01	97.87050000000000