Year	Number of Years
1960-01-01	58.3675853658537
1961-01-01	58.7815853658537
1962-01-01	59.1990731707317
1963-01-01	59.6185609756098
1964-01-01	60.0360487804878
1965-01-01	60.4490243902439
1966-01-01	60.8520000000000
1967-01-01	61.2394878048781
1968-01-01	61.6089756097561
1969-01-01	61.9564634146342
1970-01-01	62.2764634146342
1971-01-01	62.5649512195122
1972-01-01	62.8249512195122
1973-01-01	63.0604390243902
1974-01-01	63.2799268292683
1975-01-01	63.4923658536585
1976-01-01	63.7097560975610
1977-01-01	63.9405853658537
1978-01-01	64.1919024390244
1979-01-01	64.4667317073171
1980-01-01	66.6243902439025
1981-01-01	66.7060975609756
1982-01-01	66.7878048780488
1983-01-01	67.6621951219512
1984-01-01	68.5365853658537
1985-01-01	68.5365853658537
1986-01-01	68.9134146341463
1987-01-01	69.2902439024390
1988-01-01	68.8487804878049
1989-01-01	68.2902439024390
1990-01-01	68.3365853658537
1991-01-01	67.9829268292683
1992-01-01	67.7317073170732
1993-01-01	66.7268292682927
1994-01-01	65.6731707317073
1995-01-01	64.9195121951220
1996-01-01	64.1097560975610
1997-01-01	64.4634146341463
1998-01-01	64.5609756097561
1999-01-01	65.5195121951220
2000-01-01	65.5170731707317
2001-01-01	65.7682926829268
2002-01-01	65.9682926829268
2003-01-01	65.8658536585366
2004-01-01	65.8878048780488
2005-01-01	65.9097560975610
2006-01-01	66.1609756097561
2007-01-01	66.5048780487805
2008-01-01	67.0219512195122
2009-01-01	68.4292682926829
2010-01-01	68.2953658536585
2011-01-01	68.9800000000000
2012-01-01	69.6100000000000
2013-01-01	70.4500000000000
2014-01-01	71.6200000000000
2015-01-01	72.0000000000000
2016-01-01	72.3000000000000