Year	Percent of Total
1960-01-01	3.72516158960724
1961-01-01	3.75363113997821
1962-01-01	3.76126381927794
1963-01-01	3.75398651632595
1964-01-01	3.73950161552064
1965-01-01	3.72103743839633
1966-01-01	3.76664750367308
1967-01-01	3.81038212342903
1968-01-01	3.85068645363535
1969-01-01	3.88540410802168
1970-01-01	3.91490144157325
1971-01-01	3.97097469798374
1972-01-01	4.02002548044758
1973-01-01	4.06373350935712
1974-01-01	4.10530610477709
1975-01-01	4.14672027525564
1976-01-01	4.21523306198240
1977-01-01	4.28105500255802
1978-01-01	4.34089829091543
1979-01-01	4.38916762944441
1980-01-01	4.42371990481193
1981-01-01	4.46950517629613
1982-01-01	4.49831076648406
1983-01-01	4.51633862308068
1984-01-01	4.53075650155094
1985-01-01	4.54551248561523
1986-01-01	4.57796725647918
1987-01-01	4.60675012883652
1988-01-01	4.63533477059985
1989-01-01	4.66859812010355
1990-01-01	4.70855620689201
1991-01-01	4.77241669481018
1992-01-01	4.84474381825105
1993-01-01	4.91989157332742
1994-01-01	4.98939352713676
1995-01-01	5.05044431515491
1996-01-01	5.13929258450142
1997-01-01	5.21122655700537
1998-01-01	5.27442377720549
1999-01-01	5.33871036085848
2000-01-01	5.40836193425343
2001-01-01	5.49854123417111
2002-01-01	5.58946249218556
2003-01-01	5.67627346721771
2004-01-01	5.74862280186587
2005-01-01	5.80302486439873
2006-01-01	5.86651411190886
2007-01-01	5.91639119810505
2008-01-01	5.96000593729493
2009-01-01	6.00670559059689
2010-01-01	6.06189677606838
2011-01-01	6.14249665591250
2012-01-01	6.22464225847345
2013-01-01	6.31645488767240
2014-01-01	6.42949264776752
2015-01-01	6.57101023512049
2016-01-01	6.75326584820298
2017-01-01	6.95841265431691