Year	Number of Years
1960-01-01	48.4552640139166
1961-01-01	48.9884654158502
1962-01-01	49.6622455253740
1963-01-01	50.6413404510660
1964-01-01	51.8425436268996
1965-01-01	53.2155625097082
1966-01-01	54.7521461201069
1967-01-01	56.2427580998421
1968-01-01	57.6179022580812
1969-01-01	58.8570576027628
1970-01-01	59.9089070965427
1971-01-01	60.8283542094542
1972-01-01	61.6220098919438
1973-01-01	62.3191791621831
1974-01-01	63.0197288275235
1975-01-01	63.6908571728180
1976-01-01	64.3011023258151
1977-01-01	64.8842963825098
1978-01-01	65.4068036289471
1979-01-01	65.8975012640274
1980-01-01	66.3095315386110
1981-01-01	66.7239149994520
1982-01-01	67.1126717494892
1983-01-01	67.4281612698751
1984-01-01	67.7553971939424
1985-01-01	68.0414387466691
1986-01-01	68.3121182724063
1987-01-01	68.5578757360958
1988-01-01	68.7446944991245
1989-01-01	68.9543661821556
1990-01-01	69.1299358123777
1991-01-01	69.3161176451294
1992-01-01	69.4752973116647
1993-01-01	69.6508452446988
1994-01-01	69.8496122110574
1995-01-01	70.0275429856225
1996-01-01	70.3037064750155
1997-01-01	70.5849645434091
1998-01-01	70.8815161721325
1999-01-01	71.2018842162962
2000-01-01	71.5790095318242
2001-01-01	71.9521541854592
2002-01-01	72.3032306985278
2003-01-01	72.6413387994024
2004-01-01	72.9632426457228
2005-01-01	73.2337762134081
2006-01-01	73.5158126814504
2007-01-01	73.7610119967372
2008-01-01	73.9808397352339
2009-01-01	74.2072639953092
2010-01-01	74.3839146463837
2011-01-01	74.5460644618497
2012-01-01	74.7411842008234
2013-01-01	74.9190715423245
2014-01-01	75.0860081183076
2015-01-01	75.2489157797135
2016-01-01	75.3957316449765