Year	Percent of Total
1960-01-01	2.96170427080056
1961-01-01	3.00586760366384
1962-01-01	3.04026525734207
1963-01-01	3.06537535378688
1964-01-01	3.08187660231526
1965-01-01	3.09007484918217
1966-01-01	3.12373164503492
1967-01-01	3.14784442906060
1968-01-01	3.16320969428925
1969-01-01	3.17192068087679
1970-01-01	3.17678375104114
1971-01-01	3.20678991356427
1972-01-01	3.23405146787560
1973-01-01	3.25692354381393
1974-01-01	3.26577172623380
1975-01-01	3.24864959590962
1976-01-01	3.18403047090444
1977-01-01	3.14759904063544
1978-01-01	3.13337295625113
1979-01-01	3.14565184345981
1980-01-01	3.19161784182292
1981-01-01	3.20377139784087
1982-01-01	3.19849122631486
1983-01-01	3.18120180053470
1984-01-01	3.15130620759071
1985-01-01	3.10487069836253
1986-01-01	3.10582904480838
1987-01-01	3.09096082719718
1988-01-01	3.06005544782176
1989-01-01	3.01553062808003
1990-01-01	2.96041269930963
1991-01-01	2.95717398861793
1992-01-01	2.94246785489943
1993-01-01	2.91351737430635
1994-01-01	2.86366452117194
1995-01-01	2.78778656786193
1996-01-01	2.76823658843983
1997-01-01	2.73841701510604
1998-01-01	2.70301525508491
1999-01-01	2.67008981757479
2000-01-01	2.64463802223808
2001-01-01	2.64308124264126
2002-01-01	2.64726661506433
2003-01-01	2.65279044755920
2004-01-01	2.65350879794326
2005-01-01	2.64682982826485
2006-01-01	2.65501570815642
2007-01-01	2.65295514030951
2008-01-01	2.64524319754398
2009-01-01	2.63782254682486
2010-01-01	2.63342841993382
2011-01-01	2.64661248032504
2012-01-01	2.66034126578216
2013-01-01	2.67313182127584
2014-01-01	2.68239211877341
2015-01-01	2.68713354614413
2016-01-01	2.71180408207964
2017-01-01	2.73128283401695