Year	Number of Years
1960-01-01	69.2800447154363
1961-01-01	69.5899547916301
1962-01-01	69.5152634997829
1963-01-01	69.7600194611250
1964-01-01	70.2267870229951
1965-01-01	70.3376127667177
1966-01-01	70.5681320387790
1967-01-01	70.6780584015881
1968-01-01	70.7242075029447
1969-01-01	70.6796829382370
1970-01-01	70.9988105065152
1971-01-01	71.1069815707548
1972-01-01	71.4151397467929
1973-01-01	71.5354270804499
1974-01-01	71.8261862461727
1975-01-01	71.9220639580037
1976-01-01	72.1266313905516
1977-01-01	72.4103575990444
1978-01-01	72.5253302532249
1979-01-01	72.7693703790280
1980-01-01	72.8641069950217
1981-01-01	73.2032927243806
1982-01-01	73.4647948985209
1983-01-01	73.5279445288946
1984-01-01	73.8030282771145
1985-01-01	73.8772792644641
1986-01-01	74.1453000823406
1987-01-01	74.3884376430068
1988-01-01	74.5781406709545
1989-01-01	74.7440118796121
1990-01-01	74.8688090391416
1991-01-01	74.9689532653533
1992-01-01	75.2880145206698
1993-01-01	75.3947026144894
1994-01-01	75.6906959953139
1995-01-01	75.8153312081069
1996-01-01	76.0673766072879
1997-01-01	76.3609902313537
1998-01-01	76.5958524125549
1999-01-01	76.8253095130143
2000-01-01	77.1586852340439
2001-01-01	77.4932017259099
2002-01-01	77.6059246013707
2003-01-01	77.6935339059105
2004-01-01	78.1930457277725
2005-01-01	78.3649011362542
2006-01-01	78.7390425916512
2007-01-01	78.9683005321823
2008-01-01	79.1831433126818
2009-01-01	79.4423119097364
2010-01-01	79.7248489702654
2011-01-01	80.2398746474138
2012-01-01	80.2512221136288
2013-01-01	80.5327022524382
2014-01-01	80.9212410493760
2015-01-01	80.6141187762953
2016-01-01	80.6203980639033