Year	Number of Years
1960-01-01	67.6804878048781
1961-01-01	67.7780487804878
1962-01-01	67.4268292682927
1963-01-01	68.3756097560976
1964-01-01	68.6292682926829
1965-01-01	69.4292682926829
1966-01-01	69.8268292682927
1967-01-01	69.4243902439024
1968-01-01	70.2195121951220
1969-01-01	69.7195121951220
1970-01-01	69.8682926829268
1971-01-01	69.6121951219512
1972-01-01	70.6658536585366
1973-01-01	70.6634146341463
1974-01-01	71.1170731707317
1975-01-01	70.5609756097561
1976-01-01	70.6560975609756
1977-01-01	70.4024390243902
1978-01-01	70.3512195121951
1979-01-01	70.7512195121951
1980-01-01	70.0975609756098
1981-01-01	71.0512195121951
1982-01-01	71.1024390243903
1983-01-01	71.0000000000000
1984-01-01	70.8000000000000
1985-01-01	70.5487804878049
1986-01-01	70.8487804878049
1987-01-01	70.8975609756098
1988-01-01	71.3317073170732
1989-01-01	71.0439024390244
1990-01-01	70.8902439024390
1991-01-01	70.5878048780488
1992-01-01	71.0902439024390
1993-01-01	71.5951219512195
1994-01-01	71.6951219512195
1995-01-01	71.8926829268293
1996-01-01	72.2463414634146
1997-01-01	72.6463414634146
1998-01-01	72.9975609756098
1999-01-01	73.0439024390244
2000-01-01	73.7487804878049
2001-01-01	74.2000000000000
2002-01-01	74.4975609756098
2003-01-01	74.5975609756098
2004-01-01	74.8463414634146
2005-01-01	74.9951219512195
2006-01-01	75.1439024390244
2007-01-01	75.2439024390244
2008-01-01	75.5439024390244
2009-01-01	75.6951219512195
2010-01-01	76.2463414634146
2011-01-01	76.6951219512195
2012-01-01	76.7463414634146
2013-01-01	77.0000000000000
2014-01-01	77.6024390243903
2015-01-01	77.4512195121951
2016-01-01	77.4512195121951