Year	Percent of Total
1960-01-01	2.97201772124627
1961-01-01	2.98398315674798
1962-01-01	2.99576739557150
1963-01-01	3.00150952054998
1964-01-01	2.99244968884065
1965-01-01	2.96436611449538
1966-01-01	2.94090353899060
1967-01-01	2.90268573686993
1968-01-01	2.85589705105630
1969-01-01	2.80767600645060
1970-01-01	2.76129625432243
1971-01-01	2.73649891413287
1972-01-01	2.70836157341165
1973-01-01	2.67477849734333
1974-01-01	2.63312733820558
1975-01-01	2.58244148093227
1976-01-01	2.55012269116475
1977-01-01	2.51236386834968
1978-01-01	2.46791812603761
1979-01-01	2.41427563277036
1980-01-01	2.35148177802470
1981-01-01	2.30952513550248
1982-01-01	2.26231946313224
1983-01-01	2.21662947109197
1984-01-01	2.17953160081103
1985-01-01	2.15429240044333
1986-01-01	2.14962626052020
1987-01-01	2.14845789542717
1988-01-01	2.15385696438170
1989-01-01	2.17550430791011
1990-01-01	2.22276796560656
1991-01-01	2.24736835164106
1992-01-01	2.26917906709654
1993-01-01	2.27960435618991
1994-01-01	2.25326993161640
1995-01-01	2.15860857431363
1996-01-01	2.39414518129347
1997-01-01	2.62442463504897
1998-01-01	2.85091120685491
1999-01-01	3.05783869044554
2000-01-01	3.22911276432731
2001-01-01	3.14249299409826
2002-01-01	3.02478677585648
2003-01-01	2.89915862800861
2004-01-01	2.78765922037440
2005-01-01	2.69930108038104
2006-01-01	2.67364211248911
2007-01-01	2.66433036299291
2008-01-01	2.66372577568437
2009-01-01	2.66390817850580
2010-01-01	2.66200064371052
2011-01-01	2.67975558552239
2012-01-01	2.69771958149768
2013-01-01	2.72129137686417
2014-01-01	2.75709261506711
2015-01-01	2.80876659661812
2016-01-01	2.88609833532312
2017-01-01	2.97447488439728