Year	Percent
1960-01-01	65.8190345118259
1961-01-01	65.2986350132643
1962-01-01	65.9974473914856
1963-01-01	66.4426386122544
1964-01-01	66.9675383321564
1965-01-01	67.6584246425955
1966-01-01	68.4678292088653
1967-01-01	68.9698446099392
1968-01-01	69.4588130591416
1969-01-01	69.9686286906359
1970-01-01	69.6046000794090
1971-01-01	69.0201079203146
1972-01-01	69.5187939839099
1973-01-01	70.5098951557724
1974-01-01	70.8053749935455
1975-01-01	69.3362125263954
1976-01-01	70.6049589112599
1977-01-01	71.8690309736551
1978-01-01	73.6054122821884
1979-01-01	74.6021284696597
1980-01-01	74.3355413167942
1981-01-01	74.6669313056814
1982-01-01	73.5023726813062
1983-01-01	73.7121699205201
1984-01-01	75.8261930521014
1985-01-01	76.6902333092297
1986-01-01	77.3166893507974
1987-01-01	78.3679440838984
1988-01-01	79.1796271231558
1989-01-01	79.9146092107684
1990-01-01	79.6745164466218
1991-01-01	78.6282406238761
1992-01-01	78.3010912372649
1993-01-01	78.5421689307733
1994-01-01	79.2347026083011
1995-01-01	79.7497188213490
1996-01-01	80.2024608234737
1997-01-01	80.8505139446322
1998-01-01	81.1053046939037
1999-01-01	81.4120310006201
2000-01-01	81.4641176349474
2001-01-01	80.5470674488679
2002-01-01	79.3130900424254
2003-01-01	78.8209178352751
2004-01-01	78.9816482349648
2005-01-01	79.3359528265458
2006-01-01	79.8113867161010
2007-01-01	79.9145708951572
2008-01-01	79.0837465677142
2009-01-01	75.7732710347894
2010-01-01	75.0911816507562
2011-01-01	75.1169647130496
2012-01-01	75.7357961116010
2013-01-01	75.8922827561486
2014-01-01	76.6978436323153
2015-01-01	77.2426891296321
2016-01-01	77.9287976227735
2017-01-01	78.6277829741655