Year	Number of Years
1981-01-01	65.8975609756098
1982-01-01	66.1975609756098
1983-01-01	66.3975609756098
1984-01-01	66.5975609756098
1985-01-01	66.7975609756098
1986-01-01	66.9975609756098
1987-01-01	67.1975609756098
1988-01-01	67.3975609756098
1989-01-01	67.5487804878049
1990-01-01	67.7487804878049
1991-01-01	67.9487804878049
1992-01-01	68.1000000000000
1993-01-01	68.2487804878049
1994-01-01	68.4000000000000
1995-01-01	68.5512195121951
1996-01-01	68.7000000000000
1997-01-01	68.8512195121951
1998-01-01	68.9512195121951
1999-01-01	66.9512195121951
2000-01-01	67.9512195121951
2001-01-01	67.9975609756098
2002-01-01	67.9439024390244
2003-01-01	68.1951219512195
2004-01-01	68.4463414634146
2005-01-01	68.6951219512195
2006-01-01	68.9463414634146
2007-01-01	69.1975609756098
2008-01-01	69.3975609756098
2009-01-01	69.6487804878049
2010-01-01	69.9000000000000
2011-01-01	70.1487804878049
2012-01-01	70.4975609756098
2013-01-01	70.7975609756098
2014-01-01	71.0975609756098