Year	Number of Years
1960-01-01	46.6961255720296
1961-01-01	47.7849724821720
1962-01-01	48.3739503149826
1963-01-01	48.4648504288520
1964-01-01	49.0585279064656
1965-01-01	49.6522723120093
1966-01-01	50.7060640713999
1967-01-01	51.2613618221104
1968-01-01	51.8049173872822
1969-01-01	52.3544887908127
1970-01-01	52.9266132077517
1971-01-01	53.5369881910702
1972-01-01	54.1627163342096
1973-01-01	54.8591903583750
1974-01-01	55.5643277051418
1975-01-01	56.2678031696272
1976-01-01	56.9290451401483
1977-01-01	57.4901925978014
1978-01-01	57.9681098160716
1979-01-01	58.3734721872268
1980-01-01	58.7453938418689
1981-01-01	59.1410490146722
1982-01-01	59.6041023508569
1983-01-01	60.1885572367880
1984-01-01	60.8884248068402
1985-01-01	61.6929422021007
1986-01-01	62.5505954881149
1987-01-01	63.4281704347937
1988-01-01	64.2450337727598
1989-01-01	65.0462102879870
1990-01-01	65.7548049821341
1991-01-01	66.3578118654683
1992-01-01	66.8379118432950
1993-01-01	67.3271398663390
1994-01-01	67.7634825762121
1995-01-01	68.1836587492585
1996-01-01	68.5550656818562
1997-01-01	68.8859335067314
1998-01-01	69.1994339446329
1999-01-01	69.5046331610513
2000-01-01	69.7955532072658
2001-01-01	70.0793075704126
2002-01-01	70.3442224213871
2003-01-01	70.6035118462185
2004-01-01	70.8649573170077
2005-01-01	71.1119383406365
2006-01-01	71.3633866283478
2007-01-01	71.5989716185062
2008-01-01	71.8339535789692
2009-01-01	72.0600866040711
2010-01-01	72.2717696079666
2011-01-01	72.4739693721583
2012-01-01	72.6754926414208
2013-01-01	72.8849023505286
2014-01-01	73.0877371857513
2015-01-01	73.2857581521174
2016-01-01	73.4917998008008