Year	Number of Years
1960-01-01	67.8213950012551
1961-01-01	68.2620441707347
1962-01-01	68.0067749982747
1963-01-01	68.6958697107938
1964-01-01	69.0522763699495
1965-01-01	69.2768215545454
1966-01-01	69.5270082283826
1967-01-01	69.2727354454573
1968-01-01	69.5360583547124
1969-01-01	69.2757976966873
1970-01-01	69.4469707974319
1971-01-01	69.4851289765544
1972-01-01	69.9253677297177
1973-01-01	70.0676966835781
1974-01-01	70.3058738691849
1975-01-01	70.1744054785437
1976-01-01	70.3191411063472
1977-01-01	70.2422408105389
1978-01-01	70.1478390004397
1979-01-01	70.2393548096729
1980-01-01	69.8902129226427
1981-01-01	70.3714695597192
1982-01-01	70.4551336661179
1983-01-01	70.3896109824106
1984-01-01	70.3490175773774
1985-01-01	70.3127569888511
1986-01-01	70.5649221254913
1987-01-01	70.6117653159951
1988-01-01	70.8617183748472
1989-01-01	70.7319696488415
1990-01-01	70.6563673229236
1991-01-01	70.5726077380170
1992-01-01	70.7323478672471
1993-01-01	70.8462295706676
1994-01-01	70.8695267645831
1995-01-01	71.0258932341809
1996-01-01	71.3354652442541
1997-01-01	71.5175893276137
1998-01-01	71.8981182658969
1999-01-01	72.1847346480160
2000-01-01	72.7196903521431
2001-01-01	73.0979928642325
2002-01-01	73.2443135682501
2003-01-01	73.3838286851526
2004-01-01	73.7394039227775
2005-01-01	73.8400466808689
2006-01-01	74.0947247807245
2007-01-01	74.2523833324924
2008-01-01	74.5775390218700
2009-01-01	74.9318257000873
2010-01-01	75.2953487288000
2011-01-01	75.8884748834282
2012-01-01	75.9934886034530
2013-01-01	76.3551629869808
2014-01-01	76.6854764213554
2015-01-01	76.5910702431929
2016-01-01	76.6031301266380