Year	Percent of Total
1960-01-01	2.82267780281419
1961-01-01	2.85829562855404
1962-01-01	2.88322729269555
1963-01-01	2.89477614684102
1964-01-01	2.88963293342960
1965-01-01	2.86767782466426
1966-01-01	2.88538891667569
1967-01-01	2.88734055440243
1968-01-01	2.87667482687635
1969-01-01	2.85666533282733
1970-01-01	2.82947371805635
1971-01-01	2.84477184043832
1972-01-01	2.84945760078188
1973-01-01	2.84461268146247
1974-01-01	2.83123761351279
1975-01-01	2.81057378302741
1976-01-01	2.81744173804682
1977-01-01	2.81622008395198
1978-01-01	2.80866256671797
1979-01-01	2.79672912479940
1980-01-01	2.78220236435459
1981-01-01	2.80826753181318
1982-01-01	2.82778081374951
1983-01-01	2.84123496737955
1984-01-01	2.84919806180145
1985-01-01	2.85260120100510
1986-01-01	2.87165814197036
1987-01-01	2.88307612204397
1988-01-01	2.88767262093967
1989-01-01	2.88600966393724
1990-01-01	2.87904938121751
1991-01-01	2.89304448710303
1992-01-01	2.89814079231632
1993-01-01	2.89566631206321
1994-01-01	2.88667875023054
1995-01-01	2.87226730977123
1996-01-01	2.87620832196363
1997-01-01	2.87073233499854
1998-01-01	2.85762818901798
1999-01-01	2.83857712658384
2000-01-01	2.81500976416333
2001-01-01	2.81562753973401
2002-01-01	2.80689853653676
2003-01-01	2.79034880689908
2004-01-01	2.76779962801200
2005-01-01	2.74080632431914
2006-01-01	2.75463517652049
2007-01-01	2.76108193539025
2008-01-01	2.76025476730923
2009-01-01	2.75211591732632
2010-01-01	2.73747421155035
2011-01-01	2.75311609842505
2012-01-01	2.75987385425815
2013-01-01	2.75871688777088
2014-01-01	2.75040643372986
2015-01-01	2.73619013182697
2016-01-01	2.74713311988775
2017-01-01	2.75070589006249