Year	Percent of Total
1960-01-01	64.6823475718478
1961-01-01	64.4533958487999
1962-01-01	64.2900873818415
1963-01-01	64.1685508801724
1964-01-01	64.0467336901370
1965-01-01	63.9075839854093
1966-01-01	63.6772372782649
1967-01-01	63.4754016492433
1968-01-01	63.2989026313441
1969-01-01	63.1512411406200
1970-01-01	63.0373428350677
1971-01-01	62.9840701220362
1972-01-01	62.9774782882833
1973-01-01	63.0202376530532
1974-01-01	63.1170278348972
1975-01-01	63.2697731221998
1976-01-01	63.4060255379895
1977-01-01	63.5810872515980
1978-01-01	63.8237880099605
1979-01-01	64.1700849523756
1980-01-01	64.6291051344851
1981-01-01	65.0925794718116
1982-01-01	65.6602188675373
1983-01-01	66.2604273128570
1984-01-01	66.7931839177729
1985-01-01	67.2010243039562
1986-01-01	67.4079808189800
1987-01-01	67.5189389771373
1988-01-01	67.5597606481958
1989-01-01	67.5781679464384
1990-01-01	67.6017869514480
1991-01-01	67.5665039247137
1992-01-01	67.5374105052998
1993-01-01	67.5136487204863
1994-01-01	67.4932723045270
1995-01-01	67.4767979117587
1996-01-01	67.4433578247629
1997-01-01	67.4176720665462
1998-01-01	67.3937554517679
1999-01-01	67.3594946582842
2000-01-01	67.3045932657613
2001-01-01	67.2313760108404
2002-01-01	67.1450610786029
2003-01-01	67.0503973952705
2004-01-01	66.9602332098011
2005-01-01	66.8833255641913
2006-01-01	66.7595987169200
2007-01-01	66.6606804336030
2008-01-01	66.5638500711016
2009-01-01	66.4409583869716
2010-01-01	66.2762029038515
2011-01-01	66.0384566111829
2012-01-01	65.7792989137208
2013-01-01	65.4992443720004
2014-01-01	65.2126316214565
2015-01-01	64.9326600029243
2016-01-01	64.7146231591553
2017-01-01	64.4896926461045