Year	Number of Years
1960-01-01	68.5856097560976
1961-01-01	69.5773170731707
1962-01-01	69.3095121951220
1963-01-01	69.4436585365854
1964-01-01	69.9219512195122
1965-01-01	69.7221951219512
1966-01-01	70.0458536585366
1967-01-01	69.9178048780488
1968-01-01	70.0575609756098
1969-01-01	69.8331707317073
1970-01-01	69.9146341463415
1971-01-01	70.1146341463415
1972-01-01	70.4634146341463
1973-01-01	71.0146341463415
1974-01-01	71.0121951219512
1975-01-01	71.1146341463415
1976-01-01	71.5658536585366
1977-01-01	71.9146341463415
1978-01-01	72.0121951219512
1979-01-01	72.3121951219512
1980-01-01	72.4634146341463
1981-01-01	72.8121951219512
1982-01-01	72.9609756097561
1983-01-01	73.0121951219512
1984-01-01	73.6121951219512
1985-01-01	73.8146341463415
1986-01-01	74.3170731707317
1987-01-01	74.7682926829268
1988-01-01	75.2170731707317
1989-01-01	75.2658536585366
1990-01-01	75.5682926829269
1991-01-01	75.6170731707317
1992-01-01	75.8170731707317
1993-01-01	76.0682926829268
1994-01-01	76.4195121951220
1995-01-01	76.6682926829268
1996-01-01	76.8707317073171
1997-01-01	77.3195121951220
1998-01-01	77.6707317073171
1999-01-01	77.8756097560976
2000-01-01	78.1268292682927
2001-01-01	78.5756097560976
2002-01-01	78.6780487804878
2003-01-01	78.6317073170732
2004-01-01	79.1804878048781
2005-01-01	79.3317073170732
2006-01-01	79.8804878048781
2007-01-01	80.1804878048781
2008-01-01	80.4317073170732
2009-01-01	80.3317073170732
2010-01-01	80.5804878048781
2011-01-01	80.9829268292683
2012-01-01	80.9365853658537
2013-01-01	81.1365853658537
2014-01-01	81.4902439024390
2015-01-01	81.1902439024390
2016-01-01	80.8902439024390