Year	Percent of Total
1960-01-01	3.43688798356907
1961-01-01	3.46335863451309
1962-01-01	3.48203544435292
1963-01-01	3.49263880805069
1964-01-01	3.49429550443821
1965-01-01	3.48752692290562
1966-01-01	3.49192405365401
1967-01-01	3.48841507490342
1968-01-01	3.48090543844412
1969-01-01	3.47365123483250
1970-01-01	3.46912230196846
1971-01-01	3.49211399166760
1972-01-01	3.51471198103305
1973-01-01	3.53586964466465
1974-01-01	3.55372918782046
1975-01-01	3.56741884919232
1976-01-01	3.59373118794038
1977-01-01	3.61330134510090
1978-01-01	3.62789999904797
1979-01-01	3.63928501644898
1980-01-01	3.64892920839305
1981-01-01	3.67540929632960
1982-01-01	3.70120702984188
1983-01-01	3.72638607269636
1984-01-01	3.74987224852646
1985-01-01	3.77167387841651
1986-01-01	3.81936055720039
1987-01-01	3.86036179859777
1988-01-01	3.89861833356887
1989-01-01	3.93924167874382
1990-01-01	3.98507183280189
1991-01-01	4.05006873361765
1992-01-01	4.11887537243168
1993-01-01	4.19198775995474
1994-01-01	4.26899022987756
1995-01-01	4.35017030828545
1996-01-01	4.45463239463208
1997-01-01	4.56041601768626
1998-01-01	4.66743953153817
1999-01-01	4.77532069086160
2000-01-01	4.88411695844692
2001-01-01	5.04454395607722
2002-01-01	5.20280704819775
2003-01-01	5.35938095470377
2004-01-01	5.51387563920823
2005-01-01	5.66599336989201
2006-01-01	5.76655895983190
2007-01-01	5.86766760245497
2008-01-01	5.97183574599242
2009-01-01	6.08140121821945
2010-01-01	6.19820569771965
2011-01-01	6.30831886396195
2012-01-01	6.42209683183436
2013-01-01	6.54312825519939
2014-01-01	6.67637092192211
2015-01-01	6.82514406961784
2016-01-01	6.98096317539722
2017-01-01	7.15132074022823