Year	Percent of Total
1960-01-01	2.68232320804506
1961-01-01	2.68633540811023
1962-01-01	2.68581289523091
1963-01-01	2.67969966049725
1964-01-01	2.66739701934819
1965-01-01	2.65060714397909
1966-01-01	2.68534022598794
1967-01-01	2.71004506843088
1968-01-01	2.72555109394976
1969-01-01	2.73519280845883
1970-01-01	2.74329773334274
1971-01-01	2.80557648818338
1972-01-01	2.86458354136627
1973-01-01	2.92088715604484
1974-01-01	2.97269834964646
1975-01-01	3.01872398454193
1976-01-01	3.05228681062746
1977-01-01	3.06936202671504
1978-01-01	3.07179781728670
1979-01-01	3.06405449913813
1980-01-01	3.05002549377778
1981-01-01	3.05827546711309
1982-01-01	3.05800095110497
1983-01-01	3.04841475111085
1984-01-01	3.02893029501425
1985-01-01	3.00100863880007
1986-01-01	3.03325178780973
1987-01-01	3.06055463033774
1988-01-01	3.08359703060513
1989-01-01	3.10374308566303
1990-01-01	3.12267295027655
1991-01-01	3.17699308855193
1992-01-01	3.22819316455356
1993-01-01	3.27697651172228
1994-01-01	3.32356744252546
1995-01-01	3.36893304179503
1996-01-01	3.46545501967949
1997-01-01	3.55800315595766
1998-01-01	3.64841458698050
1999-01-01	3.73878598221242
2000-01-01	3.83066452716213
2001-01-01	3.92305526416337
2002-01-01	4.00938086195436
2003-01-01	4.09229670698037
2004-01-01	4.17531019888125
2005-01-01	4.26047555752918
2006-01-01	4.36552392918596
2007-01-01	4.46398199919422
2008-01-01	4.55295113670760
2009-01-01	4.62871723495685
2010-01-01	4.68953342885980
2011-01-01	4.78970387192113
2012-01-01	4.87953624859259
2013-01-01	4.95478643406694
2014-01-01	5.00836048221464
2015-01-01	5.03816895894728
2016-01-01	5.07747762586624
2017-01-01	5.09822657107194