Year	Number of Years
1960-01-01	56.0544135925826
1961-01-01	56.5364887196770
1962-01-01	57.0007149577625
1963-01-01	57.4479722436981
1964-01-01	57.8793734569607
1965-01-01	58.3002643764214
1966-01-01	58.7164449674454
1967-01-01	59.1321181244669
1968-01-01	59.5515541022400
1969-01-01	59.9755220796666
1970-01-01	60.4019911967897
1971-01-01	60.8279182550800
1972-01-01	61.2465544055346
1973-01-01	61.6541948583062
1974-01-01	62.0495604612892
1975-01-01	62.4332258252206
1976-01-01	62.8089423812347
1977-01-01	63.1805142788486
1978-01-01	63.5517973162914
1979-01-01	63.9238859023422
1980-01-01	64.2960722500190
1981-01-01	64.6662616776245
1982-01-01	65.0327272489950
1983-01-01	65.3906851145191
1984-01-01	65.7438283759256
1985-01-01	66.0907719197104
1986-01-01	66.4321230677501
1987-01-01	66.7699387069684
1988-01-01	67.1055647131615
1989-01-01	67.4427012916922
1990-01-01	67.7861914138206
1991-01-01	68.1406390682420
1992-01-01	68.5082053146936
1993-01-01	68.8859866689222
1994-01-01	69.2743833842720
1995-01-01	69.6679787914515
1996-01-01	70.0615832969396
1997-01-01	70.4494594665082
1998-01-01	70.8239105739132
1999-01-01	71.1829326838039
2000-01-01	71.5298314829906
2001-01-01	71.8501708564076
2002-01-01	72.1556211331992
2003-01-01	72.4432786850988
2004-01-01	72.7178230269670
2005-01-01	72.9825373380929
2006-01-01	73.2403874519773
2007-01-01	73.4914220767815
2008-01-01	73.7347319890022
2009-01-01	73.9804575428207
2010-01-01	74.2220028650889
2011-01-01	74.4590556400681
2012-01-01	74.6884191733679
2013-01-01	74.9110522560835
2014-01-01	75.1271940228282
2015-01-01	75.3354843581914
2016-01-01	75.5400506153496