Year	Number of Years
1980-01-01	69.5975609756098
1981-01-01	70.1878048780488
1982-01-01	69.3243902439024
1983-01-01	70.3829268292683
1984-01-01	69.5536585365854
1985-01-01	69.6975609756098
1986-01-01	68.6560975609756
1987-01-01	68.2365853658537
1988-01-01	68.7024390243902
1989-01-01	67.9707317073171
1990-01-01	68.1073170731707
1991-01-01	70.7121951219512
1992-01-01	71.2146341463415
1993-01-01	69.4682926829268
1994-01-01	70.7292682926829
1995-01-01	72.4829268292683
1996-01-01	71.5609756097561
1997-01-01	71.2121951219512
1998-01-01	71.7463414634146
1999-01-01	72.6682926829268
2000-01-01	72.7780487804878
2001-01-01	73.2536585365854
2002-01-01	71.0878048780488
2003-01-01	71.0292682926829
2004-01-01	72.6609756097561
2005-01-01	72.1317073170732
2006-01-01	72.2170731707317
2007-01-01	73.1439024390244
2008-01-01	73.1634146341463
2009-01-01	73.0829268292683
2010-01-01	73.1975609756098
2011-01-01	72.7243902439024
2012-01-01	74.2756097560976
2013-01-01	73.1195121951220
2014-01-01	73.2292682926829
2015-01-01	74.2951219512195
2016-01-01	74.3097560975610