Year	Number of Years
1960-01-01	69.8473170731707
1961-01-01	70.1026829268293
1962-01-01	69.0953658536585
1963-01-01	70.2043902439024
1964-01-01	71.5090243902439
1965-01-01	71.3251219512195
1966-01-01	71.5202439024390
1967-01-01	71.6039024390244
1968-01-01	71.3136585365854
1969-01-01	70.9285365853659
1970-01-01	70.8043902439024
1971-01-01	71.7353658536586
1972-01-01	71.0246341463415
1973-01-01	71.3321951219512
1974-01-01	71.2441463414634
1975-01-01	70.8673170731707
1976-01-01	70.9580487804878
1977-01-01	70.8095121951220
1978-01-01	70.6046341463415
1979-01-01	70.4821951219512
1980-01-01	70.4821951219512
1981-01-01	70.4607317073171
1982-01-01	70.8368292682927
1983-01-01	70.7778048780488
1984-01-01	70.3200000000000
1985-01-01	70.5012195121951
1986-01-01	72.0807317073171
1987-01-01	71.9346341463415
1988-01-01	71.7621951219512
1989-01-01	71.4253658536585
1990-01-01	71.1607317073171
1991-01-01	70.3641463414634
1992-01-01	70.2343902439025
1993-01-01	68.9104878048781
1994-01-01	68.5302439024390
1995-01-01	69.0063414634147
1996-01-01	70.1080487804878
1997-01-01	70.9090243902439
1998-01-01	71.2195121951220
1999-01-01	71.5707317073171
2000-01-01	72.0195121951219
2001-01-01	71.6585365853659
2002-01-01	71.7609756097561
2003-01-01	72.0609756097561
2004-01-01	71.9609756097561
2005-01-01	71.2536585365854
2006-01-01	71.0560975609756
2007-01-01	70.9000000000000
2008-01-01	71.8121951219512
2009-01-01	72.9146341463415
2010-01-01	73.2682926829268
2011-01-01	73.5634146341464
2012-01-01	73.8634146341464
2013-01-01	73.9146341463415
2014-01-01	74.5170731707317
2015-01-01	74.3219512195122
2016-01-01	74.3219512195122