Year	Number of Years
1960-01-01	46.8250649967610
1961-01-01	47.4076991023794
1962-01-01	47.9888783365182
1963-01-01	48.5722294115442
1964-01-01	49.1591674208195
1965-01-01	49.7443378740763
1966-01-01	50.3189999864140
1967-01-01	50.8764612861687
1968-01-01	51.4168697106976
1969-01-01	51.9459457482557
1970-01-01	52.4748194266862
1971-01-01	53.0185649936988
1972-01-01	53.5878270241579
1973-01-01	54.1826238131044
1974-01-01	54.7974316401030
1975-01-01	55.4221835559119
1976-01-01	56.0450363029634
1977-01-01	56.6563753712757
1978-01-01	57.2554464644179
1979-01-01	57.8514632690778
1980-01-01	58.4562169369463
1981-01-01	59.0821719571452
1982-01-01	59.7335345794101
1983-01-01	60.4044863062543
1984-01-01	61.0805066991468
1985-01-01	61.7399649070434
1986-01-01	62.3615506124659
1987-01-01	62.9307978780971
1988-01-01	63.4397302116826
1989-01-01	63.8893299394999
1990-01-01	64.3226994663583
1991-01-01	64.6903585209735
1992-01-01	64.9841511295156
1993-01-01	65.3450195372886
1994-01-01	65.7100196318053
1995-01-01	66.1181412186780
1996-01-01	66.4753491047707
1997-01-01	66.8165535450604
1998-01-01	67.1332679936668
1999-01-01	67.4249911264263
2000-01-01	67.6949397276557
2001-01-01	67.9487321610337
2002-01-01	68.1944834458595
2003-01-01	68.4396355867533
2004-01-01	68.6879445507359
2005-01-01	68.9380580557627
2006-01-01	69.1863650750761
2007-01-01	69.4245521980290
2008-01-01	69.6469702814488
2009-01-01	69.8514338976754
2010-01-01	70.0410543466168
2011-01-01	70.2238942443028
2012-01-01	70.4080156937082
2013-01-01	70.5982981596621
2014-01-01	70.7939574698000
2015-01-01	70.9945414725089
2016-01-01	71.1984563706590