Year	Number of Years
1960-01-01	68.4463902439024
1961-01-01	68.7377317073171
1962-01-01	68.9981219512195
1963-01-01	69.2230731707317
1964-01-01	69.4110487804878
1965-01-01	69.5610243902439
1966-01-01	69.6744634146341
1967-01-01	69.7613414634146
1968-01-01	69.8351463414634
1969-01-01	69.9048536585366
1970-01-01	69.9834634146341
1971-01-01	70.0814390243902
1972-01-01	70.2053170731707
1973-01-01	70.3581707317073
1974-01-01	70.5425609756098
1975-01-01	70.7576097560976
1976-01-01	70.9985121951220
1977-01-01	71.2562926829268
1978-01-01	71.5224634146342
1979-01-01	71.7944634146342
1980-01-01	72.0726097560976
1981-01-01	72.3576829268293
1982-01-01	72.6534634146341
1983-01-01	72.9588780487805
1984-01-01	73.2719268292683
1985-01-01	73.5857560975610
1986-01-01	73.8946097560976
1987-01-01	74.1937560975610
1988-01-01	74.4803414634146
1989-01-01	74.7524146341463
1990-01-01	75.0104146341463
1991-01-01	75.4634146341463
1992-01-01	75.7707317073171
1993-01-01	75.7121951219512
1994-01-01	76.3707317073171
1995-01-01	76.5121951219512
1996-01-01	76.5195121951220
1997-01-01	76.8804878048780
1998-01-01	77.0170731707317
1999-01-01	77.7707317073171
2000-01-01	77.8731707317073
2001-01-01	77.8243902439025
2002-01-01	77.9658536585366
2003-01-01	77.7268292682927
2004-01-01	79.1219512195122
2005-01-01	79.4317073170732
2006-01-01	79.2878048780488
2007-01-01	79.3829268292683
2008-01-01	80.5390243902439
2009-01-01	80.6365853658537
2010-01-01	80.6317073170732
2011-01-01	80.9878048780488
2012-01-01	81.3926829268293
2013-01-01	81.8000000000000
2014-01-01	82.2292682926829
2015-01-01	82.2926829268293
2016-01-01	82.2926829268293