Year	Number of Years
1960-01-01	68.7196097560976
1961-01-01	68.9431707317073
1962-01-01	69.1454390243903
1963-01-01	69.3560000000000
1964-01-01	69.5932926829268
1965-01-01	69.8707560975610
1966-01-01	70.1867073170732
1967-01-01	70.5235121951220
1968-01-01	70.8641463414634
1969-01-01	71.2026097560976
1970-01-01	71.5355365853659
1971-01-01	71.8590975609756
1972-01-01	72.1694634146342
1973-01-01	72.4647317073171
1974-01-01	72.7379024390244
1975-01-01	72.9824634146342
1976-01-01	73.1908292682927
1977-01-01	73.3613170731707
1978-01-01	73.4987317073171
1979-01-01	73.6064390243902
1980-01-01	73.7002439024390
1981-01-01	73.7974634146342
1982-01-01	73.9085853658537
1983-01-01	74.0366341463415
1984-01-01	74.1776341463415
1985-01-01	74.3091951219512
1986-01-01	74.4003902439025
1987-01-01	74.4309756097561
1988-01-01	74.3940975609756
1989-01-01	74.2989512195122
1990-01-01	74.1691707317073
1991-01-01	74.0388048780488
1992-01-01	73.9463658536585
1993-01-01	73.9208780487805
1994-01-01	73.9769024390244
1995-01-01	74.1250731707317
1996-01-01	74.3624878048781
1997-01-01	74.6666341463415
1998-01-01	75.0114146341463
1999-01-01	75.3811707317073
2000-01-01	76.6892682926829
2001-01-01	77.0668292682927
2002-01-01	77.7604878048781
2003-01-01	78.0712195121951
2004-01-01	78.1758536585366
2005-01-01	78.2960975609756
2006-01-01	78.4163414634146
2007-01-01	78.4258536585366
2008-01-01	77.9034878048781
2009-01-01	78.1498048780488
2010-01-01	78.4081707317073
2011-01-01	78.6711951219512
2012-01-01	78.9264146341463
2013-01-01	79.1673902439024
2014-01-01	79.3901219512195
2015-01-01	79.5961219512195
2016-01-01	79.7883170731707