Year	Percent of Total
1960-01-01	2.99149771897529
1961-01-01	2.83273970481375
1962-01-01	2.63422353647831
1963-01-01	2.39418434938812
1964-01-01	2.10949930831606
1965-01-01	1.78519028335761
1966-01-01	1.87402231723850
1967-01-01	1.98558626563911
1968-01-01	2.12456330082281
1969-01-01	2.29418131166795
1970-01-01	2.49900049387361
1971-01-01	2.48011910381641
1972-01-01	2.47387139708931
1973-01-01	2.46736276077436
1974-01-01	2.44530806514999
1975-01-01	2.40599077822340
1976-01-01	2.32280301108010
1977-01-01	2.22973530139358
1978-01-01	2.14422842091921
1979-01-01	2.08665161407009
1980-01-01	2.06369759480727
1981-01-01	2.20624398588688
1982-01-01	2.34434512242518
1983-01-01	2.47014786078587
1984-01-01	2.56810083810749
1985-01-01	2.63476623036025
1986-01-01	2.53205438749475
1987-01-01	2.42820837778664
1988-01-01	2.32974062880211
1989-01-01	2.24552578519612
1990-01-01	2.18236004605479
1991-01-01	2.24887938559925
1992-01-01	2.31070548493845
1993-01-01	2.35783168255898
1994-01-01	2.38560521699892
1995-01-01	2.40074933608184
1996-01-01	2.44267870350529
1997-01-01	2.47508110197838
1998-01-01	2.48377877210764
1999-01-01	2.47335223746946
2000-01-01	2.45315325888410
2001-01-01	2.38922283595848
2002-01-01	2.34143328962331
2003-01-01	2.30547661455919
2004-01-01	2.27306687489757
2005-01-01	2.24029654688428
2006-01-01	2.17859922747372
2007-01-01	2.12898847465612
2008-01-01	2.09278748239263
2009-01-01	2.07454838657957
2010-01-01	2.07976390605885
2011-01-01	2.14321085780849
2012-01-01	2.20209395816237
2013-01-01	2.25374426700096
2014-01-01	2.29505154531176
2015-01-01	2.32437101588725
2016-01-01	2.34294691654545
2017-01-01	2.37199380403381