Year	Percent of Total
1960-01-01	2.57671274379622
1961-01-01	2.58336100266007
1962-01-01	2.58695848495915
1963-01-01	2.58899783105060
1964-01-01	2.59077008884617
1965-01-01	2.59371870929953
1966-01-01	2.61162725313174
1967-01-01	2.62877902135435
1968-01-01	2.64572561337874
1969-01-01	2.66308413927250
1970-01-01	2.68154437129506
1971-01-01	2.71336443024292
1972-01-01	2.74394560932988
1973-01-01	2.77467585218418
1974-01-01	2.80658945670193
1975-01-01	2.84073488306163
1976-01-01	2.88646081227892
1977-01-01	2.93233478662162
1978-01-01	2.97872271339657
1979-01-01	3.02593530471036
1980-01-01	3.07401843502169
1981-01-01	3.14303255388872
1982-01-01	3.20970188293123
1983-01-01	3.27603676158599
1984-01-01	3.34455785119022
1985-01-01	3.41685807174639
1986-01-01	3.51534782394800
1987-01-01	3.61576637518952
1988-01-01	3.71779301425576
1989-01-01	3.82032382229175
1990-01-01	3.92314655773036
1991-01-01	4.04379314138786
1992-01-01	4.16053930675442
1993-01-01	4.27585228336464
1994-01-01	4.39346982323864
1995-01-01	4.51585020214958
1996-01-01	4.63844511840847
1997-01-01	4.76260591081834
1998-01-01	4.88758041915897
1999-01-01	5.01122775447758
2000-01-01	5.13273854667414
2001-01-01	5.25690900649249
2002-01-01	5.37464540603026
2003-01-01	5.48520477800476
2004-01-01	5.58726916121480
2005-01-01	5.68102030340027
2006-01-01	5.76178129526435
2007-01-01	5.83622051916632
2008-01-01	5.90943618650716
2009-01-01	5.98709550338983
2010-01-01	6.07357962251913
2011-01-01	6.17088000063827
2012-01-01	6.27381720244807
2013-01-01	6.38580000031124
2014-01-01	6.51112009751443
2015-01-01	6.65267656206635
2016-01-01	6.81041631862246
2017-01-01	6.98051583180381