Year	Number of Years
1960-01-01	65.1346334340412
1961-01-01	65.5902022871697
1962-01-01	65.9353248420324
1963-01-01	66.2453566382694
1964-01-01	66.5069278560786
1965-01-01	66.6851422494328
1966-01-01	66.8347772282190
1967-01-01	66.9444692373925
1968-01-01	67.0248386907337
1969-01-01	67.1666593410390
1970-01-01	67.4424810345675
1971-01-01	67.7227796687779
1972-01-01	67.8205893772566
1973-01-01	67.9368019746443
1974-01-01	68.0754582277179
1975-01-01	67.8716358239340
1976-01-01	67.8510220282288
1977-01-01	67.9082546100136
1978-01-01	68.0459045241976
1979-01-01	67.9956962886705
1980-01-01	68.0787557844892
1981-01-01	68.3317986157745
1982-01-01	68.7627829562833
1983-01-01	68.7622776941688
1984-01-01	68.6385032736282
1985-01-01	69.1331639792533
1986-01-01	70.1138858618292
1987-01-01	70.2355678035733
1988-01-01	70.3134622191348
1989-01-01	70.2369889916884
1990-01-01	70.1904310642095
1991-01-01	70.0742594936226
1992-01-01	69.2641979127571
1993-01-01	68.3247025212158
1994-01-01	68.2133334033751
1995-01-01	68.7705620329073
1996-01-01	69.4914879742368
1997-01-01	70.0702911722929
1998-01-01	70.1208406320073
1999-01-01	69.8952617209037
2000-01-01	69.7449018796277
2001-01-01	69.9980269427373
2002-01-01	69.9582786163678
2003-01-01	70.0349773881345
2004-01-01	70.3814897121121
2005-01-01	70.4825822354372
2006-01-01	71.1960422045019
2007-01-01	71.7235797554495
2008-01-01	72.0122971262566
2009-01-01	72.5134928125063
2010-01-01	72.7443117791546
2011-01-01	73.2060119506815
2012-01-01	73.6387709179037
2013-01-01	73.7614247062531
2014-01-01	73.8826972687868