Year	Number of Years
1960-01-01	69.1239024390244
1961-01-01	69.7602439024390
1962-01-01	69.1497560975610
1963-01-01	69.2480487804878
1964-01-01	70.3117073170732
1965-01-01	70.1717073170732
1966-01-01	70.9260975609756
1967-01-01	70.9565853658537
1968-01-01	70.7800000000000
1969-01-01	70.8119512195122
1970-01-01	71.5587804878049
1971-01-01	71.8068292682927
1972-01-01	72.0753658536586
1973-01-01	72.0263414634146
1974-01-01	72.7343902439025
1975-01-01	72.6473170731708
1976-01-01	72.9919512195122
1977-01-01	73.3646341463415
1978-01-01	73.6931707317073
1979-01-01	74.0026829268293
1980-01-01	73.9431707317073
1981-01-01	74.3539024390244
1982-01-01	74.8146341463415
1983-01-01	74.6402439024390
1984-01-01	75.3895121951220
1985-01-01	75.4707317073171
1986-01-01	75.7707317073171
1987-01-01	76.2195121951220
1988-01-01	76.3707317073171
1989-01-01	76.8195121951220
1990-01-01	76.9707317073171
1991-01-01	77.0195121951219
1992-01-01	77.4195121951220
1993-01-01	77.7219512195122
1994-01-01	77.9219512195122
1995-01-01	78.1707317073171
1996-01-01	78.5219512195122
1997-01-01	78.8243902439024
1998-01-01	78.9756097560976
1999-01-01	79.4243902439024
2000-01-01	79.7780487804878
2001-01-01	80.1268292682927
2002-01-01	80.2292682926829
2003-01-01	79.9829268292683
2004-01-01	80.7804878048781
2005-01-01	80.7829268292683
2006-01-01	81.2829268292683
2007-01-01	81.4341463414634
2008-01-01	81.4853658536586
2009-01-01	81.6365853658537
2010-01-01	82.0365853658537
2011-01-01	82.1878048780488
2012-01-01	82.2390243902439
2013-01-01	82.6902439024390
2014-01-01	83.0902439024390
2015-01-01	82.5439024390244
2016-01-01	82.5439024390244