Year	Percent of Total
1960-01-01	43.2845828791159
1961-01-01	43.5296142311706
1962-01-01	43.7082722522887
1963-01-01	43.8345491596099
1964-01-01	43.9157828642967
1965-01-01	43.9572434421159
1966-01-01	44.1943330133944
1967-01-01	44.3496518617891
1968-01-01	44.4440688248369
1969-01-01	44.4975861234032
1970-01-01	44.5215500353660
1971-01-01	44.7259596283125
1972-01-01	44.8671949693753
1973-01-01	44.9590650080538
1974-01-01	45.0115588042079
1975-01-01	45.0308950926967
1976-01-01	45.1885238212500
1977-01-01	45.2959922094136
1978-01-01	45.3668096025535
1979-01-01	45.4089498767424
1980-01-01	45.4242325132812
1981-01-01	45.6212892656647
1982-01-01	45.7516088857601
1983-01-01	45.8270498644019
1984-01-01	45.8595262302422
1985-01-01	45.8587588977340
1986-01-01	45.9815952560032
1987-01-01	46.0382290770014
1988-01-01	46.0441371136856
1989-01-01	46.0119043558859
1990-01-01	45.9497582936017
1991-01-01	45.9664105832287
1992-01-01	45.9317488324643
1993-01-01	45.8569241750007
1994-01-01	45.7482608556951
1995-01-01	45.6070997350120
1996-01-01	45.6314388716331
1997-01-01	45.6107361204951
1998-01-01	45.5560677418761
1999-01-01	45.4786800742914
2000-01-01	45.3859916944184
2001-01-01	45.3805924531756
2002-01-01	45.3342222236792
2003-01-01	45.2598335364569
2004-01-01	45.1673754933498
2005-01-01	45.0594043737182
2006-01-01	45.0206520642692
2007-01-01	44.9525132072104
2008-01-01	44.8545505696539
2009-01-01	44.7249298046562
2010-01-01	44.5647119862910
2011-01-01	44.4198242455239
2012-01-01	44.2351000191042
2013-01-01	44.0182943159369
2014-01-01	43.7776174551088
2015-01-01	43.5179746719456
2016-01-01	43.2874998340055
2017-01-01	43.0326342429114