Year	Percent of Total
1960-01-01	48.2948945397201
1961-01-01	48.4647168412312
1962-01-01	48.6159464638661
1963-01-01	48.7356065433884
1964-01-01	48.7848442134938
1965-01-01	48.7442813292202
1966-01-01	48.9723315055175
1967-01-01	49.0633011573462
1968-01-01	49.0478909972337
1969-01-01	48.9581276486299
1970-01-01	48.8085190065179
1971-01-01	48.8773303198544
1972-01-01	48.8682861312252
1973-01-01	48.7952891122532
1974-01-01	48.6714626032802
1975-01-01	48.4998585290766
1976-01-01	48.4219813687858
1977-01-01	48.3559133340290
1978-01-01	48.2942065740740
1979-01-01	48.2239942693193
1980-01-01	48.1285390448736
1981-01-01	48.4314908194444
1982-01-01	48.5685603420475
1983-01-01	48.5977260886624
1984-01-01	48.5670822803118
1985-01-01	48.4894505103943
1986-01-01	48.5177350766024
1987-01-01	48.5267346161624
1988-01-01	48.5259181621625
1989-01-01	48.5148722582522
1990-01-01	48.4770296152648
1991-01-01	48.5554291466577
1992-01-01	48.5167187871370
1993-01-01	48.4037449045312
1994-01-01	48.2528885418034
1995-01-01	48.0832001998875
1996-01-01	48.1026610688186
1997-01-01	48.1059592864915
1998-01-01	48.1168419717466
1999-01-01	48.1461575623806
2000-01-01	48.1839162305768
2001-01-01	48.4723210444873
2002-01-01	48.6849420473633
2003-01-01	48.8558150632818
2004-01-01	49.0100565155269
2005-01-01	49.1509789404065
2006-01-01	49.3943559836695
2007-01-01	49.5924964368833
2008-01-01	49.7543327406955
2009-01-01	49.8792044701397
2010-01-01	49.9633437556961
2011-01-01	50.0990586614329
2012-01-01	50.1781674492041
2013-01-01	50.2156691507150
2014-01-01	50.2233184193266
2015-01-01	50.2021740501629
2016-01-01	50.2314832394564
2017-01-01	50.1984975053717