Year	Number of Years
1960-01-01	68.3734178927053
1961-01-01	68.7516258027134
1962-01-01	68.7366643369618
1963-01-01	68.9481619852736
1964-01-01	69.3446273485531
1965-01-01	69.4588190527188
1966-01-01	69.7246809227308
1967-01-01	69.9535710173820
1968-01-01	69.9068619960457
1969-01-01	70.1132341772340
1970-01-01	70.4424069229468
1971-01-01	70.7243571168692
1972-01-01	71.0189020311837
1973-01-01	71.1937900635829
1974-01-01	71.6025264251358
1975-01-01	71.9493737553879
1976-01-01	72.2095119928853
1977-01-01	72.5607926718247
1978-01-01	72.7195735549794
1979-01-01	73.0431844651827
1980-01-01	73.0758753872131
1981-01-01	73.4296270668419
1982-01-01	73.7551731812243
1983-01-01	73.8597343521362
1984-01-01	74.1385313286304
1985-01-01	74.2626479149787
1986-01-01	74.5074516448515
1987-01-01	74.7746368527175
1988-01-01	74.8898279191358
1989-01-01	75.1355148652392
1990-01-01	75.2989308206495
1991-01-01	75.4741331228867
1992-01-01	75.7238816329362
1993-01-01	75.8101615575069
1994-01-01	76.0935154169434
1995-01-01	76.1627449264552
1996-01-01	76.5318213617967
1997-01-01	76.8610202126882
1998-01-01	77.0435519346130
1999-01-01	77.1885218132585
2000-01-01	77.4660886834438
2001-01-01	77.7642640421352
2002-01-01	77.9019791190628
2003-01-01	78.0295481550925
2004-01-01	78.4369622006739
2005-01-01	78.5316116309291
2006-01-01	78.8292700129985
2007-01-01	79.0599738967178
2008-01-01	79.2046776412129
2009-01-01	79.4762337538632
2010-01-01	79.6521250673758
2011-01-01	79.8897240177293
2012-01-01	80.0070586685504
2013-01-01	80.1863324096944
2014-01-01	80.4424741922433
2015-01-01	80.3320324337584
2016-01-01	80.3701464621230