Year	Number of Years
1960-01-01	40.3770124521921
1961-01-01	40.8169239695851
1962-01-01	41.2474883349662
1963-01-01	41.6669177928675
1964-01-01	42.0763403652582
1965-01-01	42.4778391720293
1966-01-01	42.8759883072861
1967-01-01	43.2754894684987
1968-01-01	43.6793484880748
1969-01-01	44.0884227155690
1970-01-01	44.5027721150378
1971-01-01	44.9215711083438
1972-01-01	45.3400587623411
1973-01-01	45.7528764478611
1974-01-01	46.1555530910984
1975-01-01	46.5439113605504
1976-01-01	46.9150058993011
1977-01-01	47.2692565722298
1978-01-01	47.6065948231844
1979-01-01	47.9270213098064
1980-01-01	48.2346233659472
1981-01-01	48.5237527406373
1982-01-01	48.7974860265022
1983-01-01	49.0543435795605
1984-01-01	49.2900266010380
1985-01-01	49.4954032032937
1986-01-01	49.6589589096254
1987-01-01	49.7748241596067
1988-01-01	49.8434333573713
1989-01-01	49.8732038682282
1990-01-01	49.8772041341593
1991-01-01	49.8732094331692
1992-01-01	49.8720928348779
1993-01-01	49.8810008910942
1994-01-01	49.8993215428742
1995-01-01	49.9272308732868
1996-01-01	49.9690748531154
1997-01-01	50.0367378912949
1998-01-01	50.1435299001349
1999-01-01	50.3047616108851
2000-01-01	50.5397008145372
2001-01-01	50.8662517837044
2002-01-01	51.2911462547755
2003-01-01	51.8130902286396
2004-01-01	52.4240620140062
2005-01-01	53.1115141838235
2006-01-01	53.8595279352860
2007-01-01	54.6415242550830
2008-01-01	55.4300875634602
2009-01-01	56.2043185446082
2010-01-01	56.9439452653290
2011-01-01	57.6367659092251
2012-01-01	58.2839362761940
2013-01-01	58.8845423720576
2014-01-01	59.4365146147731
2015-01-01	59.9391429673195
2016-01-01	60.3948379885854