Year	Percent of Total
1960-01-01	3.20845897332114
1961-01-01	3.18438107957631
1962-01-01	3.20418824176328
1963-01-01	3.23882173488836
1964-01-01	3.24533790941345
1965-01-01	3.20613029262743
1966-01-01	3.27393319867292
1967-01-01	3.27521002906064
1968-01-01	3.23601456636754
1969-01-01	3.19621102672819
1970-01-01	3.17171626047854
1971-01-01	3.16349191847596
1972-01-01	3.17825669521194
1973-01-01	3.20538542356931
1974-01-01	3.22922192331306
1975-01-01	3.24644203225366
1976-01-01	3.31901196188694
1977-01-01	3.38821395643803
1978-01-01	3.45158431340699
1979-01-01	3.50841098916630
1980-01-01	3.55778971551281
1981-01-01	3.64865268794099
1982-01-01	3.71417732141219
1983-01-01	3.76648781132410
1984-01-01	3.82157464350184
1985-01-01	3.88787279155987
1986-01-01	3.95712852802361
1987-01-01	4.04851053309734
1988-01-01	4.15146433311449
1989-01-01	4.25004707719986
1990-01-01	4.33918423515751
1991-01-01	4.48872952062555
1992-01-01	4.62968092892509
1993-01-01	4.76924629431416
1994-01-01	4.92136382354939
1995-01-01	5.09500853501272
1996-01-01	5.22647473847254
1997-01-01	5.36238991695693
1998-01-01	5.51222646722754
1999-01-01	5.68751035160370
2000-01-01	5.89474281016570
2001-01-01	6.18707312570871
2002-01-01	6.49387117216883
2003-01-01	6.80435575018671
2004-01-01	7.10997763205947
2005-01-01	7.40789252350856
2006-01-01	7.71448616827404
2007-01-01	8.00242479441534
2008-01-01	8.27006749825951
2009-01-01	8.51661370850313
2010-01-01	8.74202202142284
2011-01-01	9.02576694124470
2012-01-01	9.29977000916632
2013-01-01	9.53032212950176
2014-01-01	9.66896759694069
2015-01-01	9.69694600089202
2016-01-01	9.64746604269369
2017-01-01	9.49090785696030