Year	Percent of Total
1960-01-01	3.82220374314572
1961-01-01	3.83547006801498
1962-01-01	3.83968940310443
1963-01-01	3.83266987084548
1964-01-01	3.81323916026619
1965-01-01	3.78075963273812
1966-01-01	3.79319547946871
1967-01-01	3.79109651156934
1968-01-01	3.77584192730540
1969-01-01	3.74761516163095
1970-01-01	3.70638627338345
1971-01-01	3.71450938798865
1972-01-01	3.70778980279169
1973-01-01	3.68788565555815
1974-01-01	3.65777124809227
1975-01-01	3.61978674875512
1976-01-01	3.61770563943023
1977-01-01	3.60426413890586
1978-01-01	3.57983644878674
1979-01-01	3.54401866123044
1980-01-01	3.49688677543339
1981-01-01	3.49182578418526
1982-01-01	3.47616441052198
1983-01-01	3.45070938772366
1984-01-01	3.41569295077195
1985-01-01	3.37132122238185
1986-01-01	3.35746325676530
1987-01-01	3.33593006177600
1988-01-01	3.30717744750095
1989-01-01	3.27134512210810
1990-01-01	3.22948721801204
1991-01-01	3.20519355761331
1992-01-01	3.17310089683733
1993-01-01	3.13469256756396
1994-01-01	3.09134507547327
1995-01-01	3.04407174002910
1996-01-01	3.01502499470387
1997-01-01	2.98152297313943
1998-01-01	2.94459856857447
1999-01-01	2.90500464694300
2000-01-01	2.86331807782240
2001-01-01	2.83521481904908
2002-01-01	2.80425151324379
2003-01-01	2.77144690892455
2004-01-01	2.73769127489961
2005-01-01	2.70439809877989
2006-01-01	2.68222806926808
2007-01-01	2.65831256748977
2008-01-01	2.63223153226001
2009-01-01	2.60238693478258
2010-01-01	2.56867848296008
2011-01-01	2.54647153703039
2012-01-01	2.51944587759201
2013-01-01	2.49275350401174
2014-01-01	2.47281427572756
2015-01-01	2.46263708550815
2016-01-01	2.47222236252817
2017-01-01	2.48583321577177