Year	Number of Years
1960-01-01	47.0940384627115
1961-01-01	47.6188476831215
1962-01-01	48.2253296190508
1963-01-01	48.9406679041605
1964-01-01	49.7704046128324
1965-01-01	50.6816497772790
1966-01-01	51.6278201141743
1967-01-01	52.5599962345828
1968-01-01	53.4389152063392
1969-01-01	54.2349249406552
1970-01-01	54.9649305406358
1971-01-01	55.6172781813643
1972-01-01	56.2057717063584
1973-01-01	56.7797209844950
1974-01-01	57.3352782725009
1975-01-01	57.8416900130803
1976-01-01	58.3426091369794
1977-01-01	58.8149455353157
1978-01-01	59.2588206843693
1979-01-01	59.6555745900144
1980-01-01	60.0354874444457
1981-01-01	60.3971443741171
1982-01-01	60.7477346923954
1983-01-01	61.0602420984791
1984-01-01	61.3481774411058
1985-01-01	61.6666783613973
1986-01-01	62.0110016469680
1987-01-01	62.2919452621060
1988-01-01	62.5535371626175
1989-01-01	62.7952775437690
1990-01-01	63.0249811794047
1991-01-01	63.2456854371385
1992-01-01	63.4126230724514
1993-01-01	63.5703333648225
1994-01-01	63.7849441042640
1995-01-01	64.0310270639544
1996-01-01	64.3233531886371
1997-01-01	64.6391305394826
1998-01-01	64.9346918649654
1999-01-01	65.2066649615890
2000-01-01	65.5077877778226
2001-01-01	65.8227192955064
2002-01-01	66.1324996838922
2003-01-01	66.4540098680337
2004-01-01	66.7919943343968
2005-01-01	67.1164698477811
2006-01-01	67.4756028259230
2007-01-01	67.8243331744982
2008-01-01	68.1536334893591
2009-01-01	68.4975864346236
2010-01-01	68.8087189393515
2011-01-01	69.1236802268442
2012-01-01	69.4062791263274
2013-01-01	69.6771911735369
2014-01-01	69.9186749839553
2015-01-01	70.1491181831682
2016-01-01	70.3668241627114