Year	Number of Years
1960-01-01	69.7965121951220
1961-01-01	69.9782682926829
1962-01-01	70.1340731707317
1963-01-01	70.2729268292683
1964-01-01	70.4012926829268
1965-01-01	70.5231463414634
1966-01-01	70.6384390243903
1967-01-01	70.7451463414634
1968-01-01	70.8442926829268
1969-01-01	70.9378780487805
1970-01-01	71.0314390243903
1971-01-01	71.1285365853659
1972-01-01	71.2322439024390
1973-01-01	71.3455609756098
1974-01-01	71.4720243902439
1975-01-01	71.6166097560976
1976-01-01	71.7827804878049
1977-01-01	71.9690000000000
1978-01-01	72.1737317073171
1979-01-01	72.3934634146342
1980-01-01	72.6232439024390
1981-01-01	72.8560975609756
1982-01-01	73.0880731707317
1983-01-01	73.3136829268293
1984-01-01	73.5314634146342
1985-01-01	73.7423658536585
1986-01-01	73.9514146341463
1987-01-01	74.1625365853659
1988-01-01	74.3777073170732
1989-01-01	74.5959024390244
1990-01-01	74.8090975609756
1991-01-01	75.0052682926829
1992-01-01	75.1809512195122
1993-01-01	75.3361219512195
1994-01-01	75.4768048780488
1995-01-01	75.6175609756098
1996-01-01	75.8317073170732
1997-01-01	75.9853658536586
1998-01-01	76.1804878048781
1999-01-01	76.0829268292683
2000-01-01	76.5365853658537
2001-01-01	77.1341463414634
2002-01-01	77.6341463414634
2003-01-01	78.1390243902439
2004-01-01	78.5390243902439
2005-01-01	78.9439024390244
2006-01-01	79.2414634146342
2007-01-01	79.6414634146341
2008-01-01	80.0951219512195
2009-01-01	80.1902439024390
2010-01-01	80.7439024390244
2011-01-01	80.7463414634146
2012-01-01	80.8463414634146
2013-01-01	81.0000000000000
2014-01-01	81.3487804878049
2015-01-01	81.4536585365854
2016-01-01	81.6073170731707