Year	Percent of Total
1960-01-01	57.9267388255686
1961-01-01	57.6985740486854
1962-01-01	57.4448367790494
1963-01-01	57.2191067935984
1964-01-01	57.0880080752341
1965-01-01	57.0685821338311
1966-01-01	56.9086234561453
1967-01-01	56.8922261194590
1968-01-01	56.9654843848379
1969-01-01	57.0675931909234
1970-01-01	57.1585160245196
1971-01-01	57.1703433162225
1972-01-01	57.2079147795883
1973-01-01	57.2719089781561
1974-01-01	57.3905733920973
1975-01-01	57.5726474567934
1976-01-01	57.7096215774624
1977-01-01	57.9151824879101
1978-01-01	58.1775933076198
1979-01-01	58.4784435857304
1980-01-01	58.8002308271560
1981-01-01	59.0959394678861
1982-01-01	59.3924280295200
1983-01-01	59.6865230166814
1984-01-01	59.9747992849037
1985-01-01	60.2497160771383
1986-01-01	60.3723079524385
1987-01-01	60.5070927279908
1988-01-01	60.6456830441942
1989-01-01	60.7877333683724
1990-01-01	60.9358988160968
1991-01-01	60.9776223242469
1992-01-01	61.0870135088037
1993-01-01	61.2459437808322
1994-01-01	61.4292798130915
1995-01-01	61.6313844004373
1996-01-01	61.8858381753172
1997-01-01	62.1204082110803
1998-01-01	62.3637932436173
1999-01-01	62.6532712685874
2000-01-01	62.9968651278045
2001-01-01	63.2804594548908
2002-01-01	63.6137286116996
2003-01-01	63.9755198730276
2004-01-01	64.3287965074808
2005-01-01	64.6506287621315
2006-01-01	64.8779580429242
2007-01-01	65.0902837222325
2008-01-01	65.2749722118182
2009-01-01	65.4245945844788
2010-01-01	65.5367393812335
2011-01-01	65.5817426959779
2012-01-01	65.6041788079554
2013-01-01	65.6026623298380
2014-01-01	65.5796912606351
2015-01-01	65.5384300472566
2016-01-01	65.4546586804627
2017-01-01	65.3632133874794