Year	Percent of Total
1960-01-01	2.35928486976461
1961-01-01	2.36984422369582
1962-01-01	2.37616422247407
1963-01-01	2.37563232521244
1964-01-01	2.36530880420499
1965-01-01	2.34532193158954
1966-01-01	2.36039718735224
1967-01-01	2.36603084745512
1968-01-01	2.36409495018156
1969-01-01	2.35651409060373
1970-01-01	2.34427641878505
1971-01-01	2.36030812879602
1972-01-01	2.37199138486692
1973-01-01	2.37944394356588
1974-01-01	2.38211144646740
1975-01-01	2.38326542507900
1976-01-01	2.40527866539403
1977-01-01	2.42336415553246
1978-01-01	2.43782824403712
1979-01-01	2.45074108558343
1980-01-01	2.46106771724360
1981-01-01	2.49678861982016
1982-01-01	2.53056489966361
1983-01-01	2.56106751884702
1984-01-01	2.58705809750507
1985-01-01	2.60864167405143
1986-01-01	2.65223044940284
1987-01-01	2.68964924655851
1988-01-01	2.72196693042165
1989-01-01	2.75602207985939
1990-01-01	2.79500446694461
1991-01-01	2.87464357769820
1992-01-01	2.95131931705940
1993-01-01	3.02112146995796
1994-01-01	3.08033060795387
1995-01-01	3.12171644878291
1996-01-01	3.20981663142570
1997-01-01	3.29472684840209
1998-01-01	3.37412732521143
1999-01-01	3.44906132800519
2000-01-01	3.51943440713199
2001-01-01	3.57700135685210
2002-01-01	3.63143738693501
2003-01-01	3.68555452541889
2004-01-01	3.73772806357199
2005-01-01	3.78823067164759
2006-01-01	3.86624776117627
2007-01-01	3.94041557125763
2008-01-01	4.01355303516656
2009-01-01	4.09093326689602
2010-01-01	4.17334922028858
2011-01-01	4.26840960959339
2012-01-01	4.37137351304905
2013-01-01	4.47839824513929
2014-01-01	4.58137570062644
2015-01-01	4.67953456119362
2016-01-01	4.78687332735831
2017-01-01	4.88465967484306