Year	Percent of Total
1960-01-01	3.67825651292978
1961-01-01	3.69196013807854
1962-01-01	3.69702119913568
1963-01-01	3.69512486740352
1964-01-01	3.68802136243653
1965-01-01	3.67644520062503
1966-01-01	3.68767226843395
1967-01-01	3.69232585073758
1968-01-01	3.69172224719001
1969-01-01	3.68719288391060
1970-01-01	3.67992607431603
1971-01-01	3.69652448974805
1972-01-01	3.70876238924926
1973-01-01	3.71418442204540
1974-01-01	3.70930995056960
1975-01-01	3.69325141967190
1976-01-01	3.69197575533539
1977-01-01	3.67945806726023
1978-01-01	3.65922458764099
1979-01-01	3.63484228271605
1980-01-01	3.60853983645364
1981-01-01	3.60297706811841
1982-01-01	3.59570607779942
1983-01-01	3.58996999356085
1984-01-01	3.58980131419239
1985-01-01	3.59823173126565
1986-01-01	3.62155226020327
1987-01-01	3.64899842003899
1988-01-01	3.68063076796769
1989-01-01	3.71639129282200
1990-01-01	3.74252039170518
1991-01-01	3.80144496469918
1992-01-01	3.86313205435342
1993-01-01	3.92752522340115
1994-01-01	3.99413308845758
1995-01-01	4.06281194199965
1996-01-01	4.13129790807557
1997-01-01	4.19570569354457
1998-01-01	4.25706317649747
1999-01-01	4.31519296650309
2000-01-01	4.37053681485404
2001-01-01	4.43596149799387
2002-01-01	4.49819567568370
2003-01-01	4.55687186624536
2004-01-01	4.60960537409253
2005-01-01	4.65520762103850
2006-01-01	4.67510570967799
2007-01-01	4.68735483500222
2008-01-01	4.69616854479800
2009-01-01	4.70677283516026
2010-01-01	4.72331989895838
2011-01-01	4.74642121129684
2012-01-01	4.76969034143822
2013-01-01	4.79958163124079
2014-01-01	4.84621588735667
2015-01-01	4.91613876785465
2016-01-01	5.01887461398219
2017-01-01	5.14520299759048