Year	Number of Years
1960-01-01	67.6660975609756
1961-01-01	68.3100000000000
1962-01-01	68.5948780487805
1963-01-01	69.6580487804878
1964-01-01	70.1324390243903
1965-01-01	70.2019512195122
1966-01-01	70.9865853658537
1967-01-01	71.2765853658537
1968-01-01	71.6112195121951
1969-01-01	71.8387804878049
1970-01-01	71.9502439024390
1971-01-01	72.8829268292683
1972-01-01	73.5065853658537
1973-01-01	73.7575609756097
1974-01-01	74.3939024390244
1975-01-01	75.0573170731707
1976-01-01	75.4568292682927
1977-01-01	75.8982926829268
1978-01-01	76.0382926829268
1979-01-01	76.3375609756098
1980-01-01	76.0917073170732
1981-01-01	76.4143902439025
1982-01-01	76.9229268292683
1983-01-01	76.9614634146342
1984-01-01	77.3653658536585
1985-01-01	77.6504878048780
1986-01-01	78.0646341463415
1987-01-01	78.4836585365854
1988-01-01	78.3992682926829
1989-01-01	78.8180487804878
1990-01-01	78.8368292682927
1991-01-01	79.1007317073171
1992-01-01	79.1539024390244
1993-01-01	79.2936585365854
1994-01-01	79.6870731707317
1995-01-01	79.5363414634147
1996-01-01	80.2002439024390
1997-01-01	80.4241463414634
1998-01-01	80.5014634146342
1999-01-01	80.5707317073171
2000-01-01	81.0760975609756
2001-01-01	81.4170731707317
2002-01-01	81.5634146341463
2003-01-01	81.7600000000000
2004-01-01	82.0302439024390
2005-01-01	81.9251219512195
2006-01-01	82.3219512195122
2007-01-01	82.5070731707317
2008-01-01	82.5875609756098
2009-01-01	82.9314634146342
2010-01-01	82.8426829268293
2011-01-01	82.5912195121951
2012-01-01	83.0960975609756
2013-01-01	83.3319512195122
2014-01-01	83.5878048780488
2015-01-01	83.7939024390244
2016-01-01	83.9848780487805