Year	Percent of Total
1960-01-01	3.64332545529294
1961-01-01	3.68655747676828
1962-01-01	3.72426683943669
1963-01-01	3.75757730570445
1964-01-01	3.78819317260393
1965-01-01	3.81740044778552
1966-01-01	3.85378101378820
1967-01-01	3.88875087661448
1968-01-01	3.92244592578723
1969-01-01	3.95397695336570
1970-01-01	3.98347667725657
1971-01-01	4.02591041315661
1972-01-01	4.06193450798916
1973-01-01	4.09380837426995
1974-01-01	4.12445443534390
1975-01-01	4.15527407024295
1976-01-01	4.20248664393785
1977-01-01	4.24769099665288
1978-01-01	4.28937458740244
1979-01-01	4.32457758057681
1980-01-01	4.35258403519260
1981-01-01	4.38481572855685
1982-01-01	4.40948428352361
1983-01-01	4.43114272867902
1984-01-01	4.45515121245079
1985-01-01	4.48459910905319
1986-01-01	4.53304988071777
1987-01-01	4.58215995164938
1988-01-01	4.63330803816623
1989-01-01	4.68751799716179
1990-01-01	4.74528321601346
1991-01-01	4.82211595686220
1992-01-01	4.89911625417974
1993-01-01	4.97491973190498
1994-01-01	5.04713779831843
1995-01-01	5.11524769722764
1996-01-01	5.20932113022764
1997-01-01	5.29794074532733
1998-01-01	5.38420814165704
1999-01-01	5.47202214360943
2000-01-01	5.56386063165981
2001-01-01	5.67124404430850
2002-01-01	5.78104734608447
2003-01-01	5.89308189387820
2004-01-01	6.00624398428130
2005-01-01	6.12078783981434
2006-01-01	6.23866707594663
2007-01-01	6.35710592656092
2008-01-01	6.47902125629336
2009-01-01	6.60766467967683
2010-01-01	6.74582300079060
2011-01-01	6.89570032271478
2012-01-01	7.05006326922203
2013-01-01	7.21433894710719
2014-01-01	7.39519614308171
2015-01-01	7.59713132036278
2016-01-01	7.81225694492347
2017-01-01	8.04498278027010