Year	Number of Years
1960-01-01	45.7246328287819
1961-01-01	46.1728710193706
1962-01-01	46.8938054373315
1963-01-01	47.9247573083867
1964-01-01	49.2727307302297
1965-01-01	50.8604930215837
1966-01-01	52.5717041039774
1967-01-01	54.2717841103696
1968-01-01	55.8405546848831
1969-01-01	57.2214721688488
1970-01-01	58.3893359716109
1971-01-01	59.3611065446416
1972-01-01	60.2059083010161
1973-01-01	60.9838695111030
1974-01-01	61.7131825652796
1975-01-01	62.4044621294699
1976-01-01	63.0638827717046
1977-01-01	63.6826419272523
1978-01-01	64.2552363611498
1979-01-01	64.7809151678146
1980-01-01	65.2576415469816
1981-01-01	65.6869366561996
1982-01-01	66.0749895395082
1983-01-01	66.4243109149731
1984-01-01	66.7411509624657
1985-01-01	67.0280260710465
1986-01-01	67.2882618423500
1987-01-01	67.5226713327208
1988-01-01	67.7349807868417
1989-01-01	67.9309780860977
1990-01-01	68.1151334349222
1991-01-01	68.2910304332470
1992-01-01	68.4630313396003
1993-01-01	68.6380499540564
1994-01-01	68.8247678682381
1995-01-01	69.0347608619926
1996-01-01	69.2803672304857
1997-01-01	69.5620641870828
1998-01-01	69.8798049531817
1999-01-01	70.2263459103254
2000-01-01	70.5943126819570
2001-01-01	70.9717036715478
2002-01-01	71.3429713365949
2003-01-01	71.6966983127618
2004-01-01	72.0258050184806
2005-01-01	72.3253262185058
2006-01-01	72.5950769173238
2007-01-01	72.8412906714921
2008-01-01	73.0702965937426
2009-01-01	73.2836488892432
2010-01-01	73.4823446954104
2011-01-01	73.6691348505637
2012-01-01	73.8458176432270
2013-01-01	74.0134910071165
2014-01-01	74.1762412179218
2015-01-01	74.3349735695129
2016-01-01	74.4925325576175