Year	Number of Years
1960-01-01	71.1268292682927
1961-01-01	70.8780487804878
1962-01-01	70.9268292682927
1963-01-01	70.8268292682927
1964-01-01	71.6243902439024
1965-01-01	71.6243902439024
1966-01-01	71.5731707317073
1967-01-01	72.1243902439024
1968-01-01	71.7243902439025
1969-01-01	71.7219512195122
1970-01-01	71.9731707317073
1971-01-01	72.2731707317073
1972-01-01	72.1243902439024
1973-01-01	72.3243902439024
1974-01-01	72.5243902439024
1975-01-01	72.7243902439024
1976-01-01	72.7756097560976
1977-01-01	73.2243902439024
1978-01-01	73.1756097560976
1979-01-01	73.2756097560976
1980-01-01	73.6756097560976
1981-01-01	74.0268292682927
1982-01-01	74.1780487804878
1983-01-01	74.3780487804878
1984-01-01	74.7780487804878
1985-01-01	74.6292682926829
1986-01-01	74.9292682926829
1987-01-01	75.2804878048780
1988-01-01	75.3804878048781
1989-01-01	75.5829268292683
1990-01-01	75.8804878048781
1991-01-01	76.0829268292683
1992-01-01	76.4341463414634
1993-01-01	76.3853658536585
1994-01-01	76.8853658536585
1995-01-01	76.8365853658537
1996-01-01	77.0878048780488
1997-01-01	77.2109756097561
1998-01-01	77.1902439024390
1999-01-01	77.3902439024390
2000-01-01	77.7414634146342
2001-01-01	77.9926829268293
2002-01-01	78.1439024390244
2003-01-01	78.4463414634146
2004-01-01	78.7463414634146
2005-01-01	79.0487804878049
2006-01-01	79.2487804878049
2007-01-01	79.4487804878049
2008-01-01	79.6000000000000
2009-01-01	80.0512195121951
2010-01-01	80.4024390243902
2011-01-01	80.9512195121951
2012-01-01	80.9048780487805
2013-01-01	81.0048780487805
2014-01-01	81.3048780487805
2015-01-01	80.9560975609756
2016-01-01	80.9560975609756