Year	Percent of Total
1960-01-01	3.05935467632010
1961-01-01	3.11220060229975
1962-01-01	3.16252746963302
1963-01-01	3.20335351246546
1964-01-01	3.22747653933268
1965-01-01	3.23259745812138
1966-01-01	3.27006390197251
1967-01-01	3.29177673010206
1968-01-01	3.30343031323194
1969-01-01	3.31131965233877
1970-01-01	3.31870738631794
1971-01-01	3.36727914353566
1972-01-01	3.41163673080138
1973-01-01	3.44895373853626
1974-01-01	3.47647691870255
1975-01-01	3.49380829011708
1976-01-01	3.53738972610569
1977-01-01	3.57120070849286
1978-01-01	3.59671327589313
1979-01-01	3.61535300772664
1980-01-01	3.62841232365145
1981-01-01	3.66474311786860
1982-01-01	3.69114134612719
1983-01-01	3.70900550304858
1984-01-01	3.72062787251885
1985-01-01	3.72820513924662
1986-01-01	3.75895430584051
1987-01-01	3.78365813610971
1988-01-01	3.80290941577800
1989-01-01	3.81729178571589
1990-01-01	3.82817358090853
1991-01-01	3.88489607694569
1992-01-01	3.93520534608826
1993-01-01	3.98023882525091
1994-01-01	4.02167545308958
1995-01-01	4.06109721101251
1996-01-01	4.13730479450242
1997-01-01	4.20751335917782
1998-01-01	4.27340189858906
1999-01-01	4.33682246094153
2000-01-01	4.39923069930355
2001-01-01	4.48367959970577
2002-01-01	4.56461693562521
2003-01-01	4.64035223417959
2004-01-01	4.70824665043920
2005-01-01	4.76817014176276
2006-01-01	4.84686789420271
2007-01-01	4.91807100782417
2008-01-01	4.98431301128886
2009-01-01	5.04828624080824
2010-01-01	5.11307370295705
2011-01-01	5.20596827627403
2012-01-01	5.29652122999522
2013-01-01	5.39264187714255
2014-01-01	5.50406936289318
2015-01-01	5.63624534413776
2016-01-01	5.80790445040846
2017-01-01	5.98896924939209