Year	Percent of Total
1960-01-01	5.02138079027086
1961-01-01	4.98441319016800
1962-01-01	4.92285736203182
1963-01-01	4.83758635457176
1964-01-01	4.73096116923469
1965-01-01	4.60503822431312
1966-01-01	4.64681624020053
1967-01-01	4.67139520353657
1968-01-01	4.68009270702360
1969-01-01	4.67351256427895
1970-01-01	4.65271911933359
1971-01-01	4.66959979466312
1972-01-01	4.67234662486484
1973-01-01	4.66060202172674
1974-01-01	4.63332007283652
1975-01-01	4.59027338587790
1976-01-01	4.57063318806647
1977-01-01	4.53521964421095
1978-01-01	4.48702559466143
1979-01-01	4.42829483607414
1980-01-01	4.36085027164519
1981-01-01	4.31323243619062
1982-01-01	4.25708185473790
1983-01-01	4.19255292579189
1984-01-01	4.11985703491059
1985-01-01	4.03973260728465
1986-01-01	3.99302441635906
1987-01-01	3.93999201369358
1988-01-01	3.88146254150570
1989-01-01	3.81789189081530
1990-01-01	3.75020889843037
1991-01-01	3.69700042664345
1992-01-01	3.64122605430096
1993-01-01	3.58488765272975
1994-01-01	3.53007059581185
1995-01-01	3.47838426106390
1996-01-01	3.43285377270641
1997-01-01	3.38714147692983
1998-01-01	3.34208877070723
1999-01-01	3.29857093938295
2000-01-01	3.25730550654964
2001-01-01	3.23321510080994
2002-01-01	3.20770886397637
2003-01-01	3.18407351585089
2004-01-01	3.16625643031926
2005-01-01	3.15604984825660
2006-01-01	3.17398443402472
2007-01-01	3.19430722770084
2008-01-01	3.21328848065222
2009-01-01	3.22574045474496
2010-01-01	3.22989058140444
2011-01-01	3.23678690242117
2012-01-01	3.23626088994322
2013-01-01	3.23202142726273
2014-01-01	3.22829102243749
2015-01-01	3.22771888525969
2016-01-01	3.23571888849993
2017-01-01	3.24441654261767