Year	Percent of Total
1960-01-01	8.04706364754658
1961-01-01	8.12353850532696
1962-01-01	8.19709814953670
1963-01-01	8.26706926565086
1964-01-01	8.34116764727630
1965-01-01	8.42012760447812
1966-01-01	8.49735883891482
1967-01-01	8.57037198393119
1968-01-01	8.64029969599688
1969-01-01	8.70755641815283
1970-01-01	8.76894328510072
1971-01-01	8.86483041026037
1972-01-01	8.94349994521957
1973-01-01	9.01350475062731
1974-01-01	9.08179975227660
1975-01-01	9.16173705690833
1976-01-01	9.29270828131880
1977-01-01	9.43644102111884
1978-01-01	9.58643765335713
1979-01-01	9.73096332202580
1980-01-01	9.86585590242791
1981-01-01	9.93566399611557
1982-01-01	9.98975431797624
1983-01-01	10.03732750329420
1984-01-01	10.09095172691030
1985-01-01	10.16176701906600
1986-01-01	10.24921111115660
1987-01-01	10.34704682339230
1988-01-01	10.45140056695330
1989-01-01	10.55848945973460
1990-01-01	10.66643664009600
1991-01-01	10.79092010061170
1992-01-01	10.90482066184640
1993-01-01	11.01745248538010
1994-01-01	11.13156167731520
1995-01-01	11.24878096170440
1996-01-01	11.31704608550800
1997-01-01	11.40116387797980
1998-01-01	11.49308380797400
1999-01-01	11.56727966315180
2000-01-01	11.60982045750350
2001-01-01	11.67768913459190
2002-01-01	11.70438336096230
2003-01-01	11.71618880924600
2004-01-01	11.74666098713860
2005-01-01	11.80863722502280
2006-01-01	11.78668659584690
2007-01-01	11.78800786369590
2008-01-01	11.81759112723720
2009-01-01	11.88695481609440
2010-01-01	12.00519467545770
2011-01-01	12.26431429295830
2012-01-01	12.57933314082440
2013-01-01	12.93983102415990
2014-01-01	13.32190623487250
2015-01-01	13.71414382742400
2016-01-01	14.07538634600000
2017-01-01	14.43086336840530