Year	Number of Years
1960-01-01	34.671
1961-01-01	34.941
1962-01-01	35.257
1963-01-01	35.626
1964-01-01	36.049
1965-01-01	36.520
1966-01-01	37.030
1967-01-01	37.564
1968-01-01	38.113
1969-01-01	38.674
1970-01-01	39.254
1971-01-01	39.867
1972-01-01	40.522
1973-01-01	41.217
1974-01-01	41.943
1975-01-01	42.686
1976-01-01	43.431
1977-01-01	44.156
1978-01-01	44.838
1979-01-01	45.458
1980-01-01	45.996
1981-01-01	46.435
1982-01-01	46.778
1983-01-01	47.032
1984-01-01	47.206
1985-01-01	47.298
1986-01-01	47.309
1987-01-01	47.260
1988-01-01	47.189
1989-01-01	47.138
1990-01-01	47.183
1991-01-01	47.406
1992-01-01	47.839
1993-01-01	48.475
1994-01-01	49.283
1995-01-01	50.163
1996-01-01	50.984
1997-01-01	51.641
1998-01-01	52.082
1999-01-01	52.314
2000-01-01	52.423
2001-01-01	52.543
2002-01-01	52.814
2003-01-01	53.323
2004-01-01	54.084
2005-01-01	55.052
2006-01-01	56.136
2007-01-01	57.207
2008-01-01	58.167
2009-01-01	58.977
2010-01-01	59.631
2011-01-01	60.155
2012-01-01	60.615
2013-01-01	61.066
2014-01-01	61.527
2015-01-01	62.007
2016-01-01	62.505