Year	Percent
1960-01-01	65.1868440581142
1961-01-01	65.2990201658849
1962-01-01	65.1179956488689
1963-01-01	65.2225606939348
1964-01-01	65.2160508673743
1965-01-01	65.4061137911397
1966-01-01	65.9049692282880
1967-01-01	66.3860572154615
1968-01-01	66.4813040456170
1969-01-01	67.0001354370094
1970-01-01	67.3693394651459
1971-01-01	67.2380332191720
1972-01-01	67.6200458797537
1973-01-01	68.2289113333224
1974-01-01	68.9086457752995
1975-01-01	68.9953235288939
1976-01-01	69.5626741923232
1977-01-01	70.4142382924630
1978-01-01	71.4813717269576
1979-01-01	72.1886008200336
1980-01-01	72.4451776450679
1981-01-01	72.7056640205962
1982-01-01	72.9643223843908
1983-01-01	73.1566021593524
1984-01-01	73.7642885320415
1985-01-01	74.4360346853096
1986-01-01	75.0031083789862
1987-01-01	75.4920844171702
1988-01-01	75.8861904833287
1989-01-01	76.5850495542888
1990-01-01	76.5325948284207
1991-01-01	76.2493108984482
1992-01-01	76.6363548362238
1993-01-01	76.5877438930790
1994-01-01	76.7335721380636
1995-01-01	76.8737634086734
1996-01-01	77.0632461644139
1997-01-01	77.3666208825724
1998-01-01	77.3636700715003
1999-01-01	77.2309942339816
2000-01-01	77.1990783408761
2001-01-01	76.8120491613466
2002-01-01	76.4004152756496
2003-01-01	75.8200605989860
2004-01-01	75.4461112914102
2005-01-01	75.4086682387445
2006-01-01	75.5389405705323
2007-01-01	75.3020784222624
2008-01-01	75.2913862498356
2009-01-01	74.6241781800198
2010-01-01	73.9099136128197
2011-01-01	73.2929806862772
2012-01-01	73.1062732373767
2013-01-01	72.8111937098818
2014-01-01	72.6960534819419
2015-01-01	72.6062441302359
2016-01-01	72.9505243997170
2017-01-01	73.3405145092676