Year	Number of Years
1960-01-01	49.5143922669332
1961-01-01	50.0373561898401
1962-01-01	50.7005485471229
1963-01-01	51.5602932075425
1964-01-01	52.6536416875966
1965-01-01	53.9196736377547
1966-01-01	55.2691180296231
1967-01-01	56.6210433224308
1968-01-01	57.8950324292340
1969-01-01	59.0256575677309
1970-01-01	60.0376965012218
1971-01-01	60.8943932876126
1972-01-01	61.6193183774928
1973-01-01	62.2999056657118
1974-01-01	62.9301480570822
1975-01-01	63.4551441201060
1976-01-01	63.9673799356125
1977-01-01	64.4337062736107
1978-01-01	64.8623032917998
1979-01-01	65.2228270469042
1980-01-01	65.5838188428859
1981-01-01	65.9343907420942
1982-01-01	66.2877036278956
1983-01-01	66.5833993856087
1984-01-01	66.8471966831222
1985-01-01	67.1872087599625
1986-01-01	67.5900054826482
1987-01-01	67.8539782692374
1988-01-01	68.1033426506424
1989-01-01	68.3112798343437
1990-01-01	68.5073333087745
1991-01-01	68.6906307139762
1992-01-01	68.7649053532548
1993-01-01	68.8195126569228
1994-01-01	68.9959557320353
1995-01-01	69.2394471637589
1996-01-01	69.5696541904713
1997-01-01	69.9160977528952
1998-01-01	70.2462493941434
1999-01-01	70.5108919724169
2000-01-01	70.8273296477610
2001-01-01	71.1606423087190
2002-01-01	71.4749870541955
2003-01-01	71.7946541487519
2004-01-01	72.1303351392015
2005-01-01	72.4205288506414
2006-01-01	72.7681198235190
2007-01-01	73.0834081711375
2008-01-01	73.3561712354907
2009-01-01	73.6538065259833
2010-01-01	73.8936137851468
2011-01-01	74.1790198545248
2012-01-01	74.4235102280132
2013-01-01	74.6679533053731
2014-01-01	74.8768031104745
2015-01-01	75.0888384917493
2016-01-01	75.2906209723914