Year	Percent of Total
1960-01-01	42.9888154273605
1961-01-01	43.2359923692819
1962-01-01	43.4281888103293
1963-01-01	43.5723664864867
1964-01-01	43.6662212560582
1965-01-01	43.7107779539672
1966-01-01	43.9366260163275
1967-01-01	44.0729739675571
1968-01-01	44.1454495139624
1969-01-01	44.1829097457128
1970-01-01	44.2017670211070
1971-01-01	44.3921654375498
1972-01-01	44.5356363684666
1973-01-01	44.6397541537634
1974-01-01	44.7067151828847
1975-01-01	44.7405950750344
1976-01-01	44.9121454969619
1977-01-01	45.0216092907670
1978-01-01	45.0892422259183
1979-01-01	45.1323118536804
1980-01-01	45.1574837942050
1981-01-01	45.3514970118197
1982-01-01	45.4848329176888
1983-01-01	45.5648093597769
1984-01-01	45.5945968683411
1985-01-01	45.5770674732041
1986-01-01	45.6749544833307
1987-01-01	45.7027839498196
1988-01-01	45.6717984231924
1989-01-01	45.5901684221521
1990-01-01	45.4622207534910
1991-01-01	45.4198095710341
1992-01-01	45.3168086899179
1993-01-01	45.1664439053379
1994-01-01	44.9829984283561
1995-01-01	44.7769741907700
1996-01-01	44.7335128506462
1997-01-01	44.6538435365400
1998-01-01	44.5478739607942
1999-01-01	44.4226610572741
2000-01-01	44.2838682851785
2001-01-01	44.2762204745713
2002-01-01	44.2301117034715
2003-01-01	44.1605833084071
2004-01-01	44.0824463090453
2005-01-01	44.0018341599742
2006-01-01	43.9928380561206
2007-01-01	43.9613428298554
2008-01-01	43.9076118840357
2009-01-01	43.8287160861344
2010-01-01	43.7239816410984
2011-01-01	43.6492051984295
2012-01-01	43.5394332723728
2013-01-01	43.3992445508755
2014-01-01	43.2323454269432
2015-01-01	43.0409748560019
2016-01-01	42.8783870025764
2017-01-01	42.6806192679201