Year	Number of Years
1960-01-01	46.6316434808415
1961-01-01	47.2212607698649
1962-01-01	47.8076039450309
1963-01-01	48.3941859013758
1964-01-01	48.9834233572063
1965-01-01	49.5709643829269
1966-01-01	50.1496425730307
1967-01-01	50.7140141761342
1968-01-01	51.2652490551905
1969-01-01	51.8080930116037
1970-01-01	52.3601623420991
1971-01-01	52.9440837276684
1972-01-01	53.5708076100299
1973-01-01	54.2372211688273
1974-01-01	54.9318527344860
1975-01-01	55.6174065971932
1976-01-01	56.2454847085152
1977-01-01	56.7863286073223
1978-01-01	57.2315468222993
1979-01-01	57.5960478026480
1980-01-01	57.9249961283021
1981-01-01	58.2842900014332
1982-01-01	58.7334423049359
1983-01-01	59.3098078446960
1984-01-01	60.0206907402034
1985-01-01	60.8500340861286
1986-01-01	61.7582406268182
1987-01-01	62.6819278069047
1988-01-01	63.5659064273248
1989-01-01	64.3816304393292
1990-01-01	65.1328157457343
1991-01-01	65.7599397085628
1992-01-01	66.3106009000628
1993-01-01	66.8042996078802
1994-01-01	67.2492208066518
1995-01-01	67.6527677731247
1996-01-01	68.0211238284279
1997-01-01	68.3604948315203
1998-01-01	68.6769919257675
1999-01-01	68.9767906973164
2000-01-01	69.2655244373117
2001-01-01	69.5464290602042
2002-01-01	69.8198464824074
2003-01-01	70.0861225293243
2004-01-01	70.3479018041243
2005-01-01	70.6050542444019
2006-01-01	70.8568065283290
2007-01-01	71.0988525700465
2008-01-01	71.3286692527803
2009-01-01	71.5462921103223
2010-01-01	71.7548050000704
2011-01-01	71.9593278782990
2012-01-01	72.1641462021744
2013-01-01	72.3714973554048
2014-01-01	72.5788298451069
2015-01-01	72.7857363593388
2016-01-01	72.9919202205410