Year	Percent of Total
1960-01-01	4.82749959445529
1961-01-01	4.90674806399655
1962-01-01	4.94984792212980
1963-01-01	4.96132419657650
1964-01-01	4.95116862134882
1965-01-01	4.92447097163461
1966-01-01	4.89999219271537
1967-01-01	4.86740863167208
1968-01-01	4.83363488150151
1969-01-01	4.80609621208584
1970-01-01	4.78720700643169
1971-01-01	4.83641471470331
1972-01-01	4.87952118053764
1973-01-01	4.90616215225892
1974-01-01	4.90376627213793
1975-01-01	4.86831016232882
1976-01-01	4.81423400499058
1977-01-01	4.73540992274401
1978-01-01	4.64665635018511
1979-01-01	4.56389544740268
1980-01-01	4.49473314149555
1981-01-01	4.47257676055323
1982-01-01	4.45242717245111
1983-01-01	4.42783520987091
1984-01-01	4.39043552154092
1985-01-01	4.33632467358801
1986-01-01	4.30868857046140
1987-01-01	4.26519283760782
1988-01-01	4.21464372636638
1989-01-01	4.16654211474222
1990-01-01	4.12696959222030
1991-01-01	4.07887036400805
1992-01-01	4.02709692257907
1993-01-01	3.96659597030753
1994-01-01	3.89103949316289
1995-01-01	3.79993551023285
1996-01-01	3.81245178749417
1997-01-01	3.80447789630067
1998-01-01	3.77939284850080
1999-01-01	3.74086446967842
2000-01-01	3.69081802392222
2001-01-01	3.71860866460367
2002-01-01	3.73583220899479
2003-01-01	3.74314680437989
2004-01-01	3.73961884500038
2005-01-01	3.72487676364347
2006-01-01	3.76601048001338
2007-01-01	3.79890186636416
2008-01-01	3.82043360852256
2009-01-01	3.82541021605980
2010-01-01	3.81254492839106
2011-01-01	3.83209802152151
2012-01-01	3.83807128496432
2013-01-01	3.84028898190273
2014-01-01	3.85290721694616
2015-01-01	3.88480948322688
2016-01-01	3.94645831172512
2017-01-01	4.03092422504923